Studies in the Formation of the Mountains in the Sierra Nevada, California.

• Main Author: Muir, John
• Format: Text
• Language: English
• Published: Scholarly Commons 1874
• Subjects: John Muir; Bibliography; Kimes; William F. Kimes; Maymie B. Kimes; pamphlets; journal articles; speeches; writing; naturalist; annotation; Elliott; Hoffman Glacier; Indian; Lied; Pinnacle; Rani; Ice Sheet; Newfoundland
• Online Access: https://scholarlycommons.pacific.edu/jmb/17; https://scholarlycommons.pacific.edu/cgi/viewcontent.cgi?article=1016&context=jmb

I-. NAM li.VI. Ill- i' -i.'l . f., \ ,\ !".'l I'- !!Kll'll-illi.-tl l.i-i T ;. -. [t i-.-in - - :.-.- -ii:i - - t-a-i and sometimes west, in North ( there :-: ' ' '|'i,:' "'*'' dip- i-. these dikes occur en a \a-!lv I :i i -j i-r Sf-.-sh in North Carol hi.-!, in (he tm- case formii in-idefablc exti !:'. and in/the "flu r. limit -d cut uji !' tra|j i in ( irtirti-eticul \ li. .iiitaili -!i:i. -1- to i.ili'ou ;i i.= -- h._ a mile ill -nt iiW-n ion-1! n-ilea! i-Jcnl: and in life la! ca-i the\ are Lii-niTa!! \ transverse to the strike, while in tin former the\ are luevalefMh eoiueidcnl v./fh it. rVa lev, feel or rods in breaihvfi. and rareh reacii- lii II,.- itii place, tin- formation isAerv barren of org ' n mains m its ;, iritit-rii outi-rops. imart.:iiif! vVry readily subject to (lenwfation, it- remnants e\ i re where lying/it trough-like depressions, tuviiig evidently suffered a much gneatcr aniontit of waste from erosion than the enclosing ami ui/ieilving formations. We have sVmc iiin! of the atnotmt of tl/fs waste in the fact that the whole ttrU-kness of the formation has been swept away from the brottd-baekeorler of the siat'-./ati't in the oeeurrenee of :i third outcrop eastwarVf the Ik-ej* Kiver belt and several mile- from ii. of the same eastvrahih /'.bus adding many thousand feet to the former estimates wliich were based upon the last named outcrop. Again in North f lc it-ait***- o*w / N \ n uM.'Hi-ionv. Ill Carolina the heavies! conglomerates are found along tho castt-Hf iu.'injjn- of the format ion. the embedded bou'di r-:. of:, n moreifiau :i foot th dialui-l. i ei-i,.-ain-r of the triiibCii rock~, Ivijje between it and the At l.-mi ie.JTom uhicli. in laryre pata. its material wits derive.!. A iii I this liijjy'have been the last of Ilia! eastward ;7H(j northe.'tst- wai'i'l eon'iMi-nia! area I'eijuiii-d iy In.-Hail'- i'.'.:.'i it -iNaiis verv r:iiiin:iLf ihi-ory of the format ion of the palaeozoic rocks orsNew York' and of the Appalachians and the northwest, which are w -tiibnted as to indicate an eastern origin. StfWES SS Titf; FjRi.Vi'Sox or M'CSTAIXS IS rut; St.saw X:rAiA. C.vi.iFoi.-NiA. Bv John Jlnu. vf Oakhri, ('a!. .UISIKU'I. ' TitEss studies in mountain building refer particularly to that portion of the Sierra which is embraced between Lat. ;('.', .'In and off3. It measures about two hundred miles in length by .ukkiI sixty in width, and attains an elevation along the axis, from $e*t thousand six hundred to nearly fifteen thousand feet above the sea, : Ti/:- jKifii T w:io-n--- -ampsnicil by a targe imak-r -A ii a-tr.i --. .-.-.i-! it i jrfesatt* t" In- rca-L-Ui--i that th- ''.n-!?--:' iUv A-MH-atn.:, -x-.-ia i a.t , .i - : ll.t-ir !k.4 m--| - .iia-.-l A3 I'llis- Tili- ii.i- no ,--Mt:it.-l tin- alil.n-vait;.M rf -t .-;; --!- of r'le ' muu:.:. ti-.a. ami in jonticr t-i tiae ;ui!:iar I line; -I te lhal i.- !:a- n-A rtad i-n-. f= iiwiux ia i.s ab-euce frtau OjUiai.!, vvlioa- tlu-y wtav ---ut.—Kme- 50 '. N'A It'iiAl. IIJSTOKY. All the individual mountains distributed over this vast area. whether the precipitous ranks marshalled along the .smniuit. or the more beautiful and highly specialized domes and mounts ttot- ted ui i- the broad undulating flanks, or the immense bosses and angles projecting horizontally from the sides of valleys, have ail been brought into relief during the glacial epoch, by the direct mechanical action of the (Ce-sfeeet and the glaciers into which it afterwards separated. The chief phenomena presented are : !. Scratched and polished ' surfaces. '2. Moraines. *'!. Moutonneed rock formsand sculpture in general, as seen ill valleys, rltlgCS, lake basins and separate mountains. The polished surfaces ocelli- in the summit and upper half of the middle region, in irregular patches, some of which are several acres in extent, and though they have been subjected to corroding influences for thousands of years, their mechanical excellence is such that they still reflect the sunbeams like glass. The most extensive areas arc found in the upper half of the middle region where the granite is most solid in structure and contains the greatest quantity of silex. They are brighter, and extend farther down on the axis of the range on the north xi'lta of valleys, because when wet by corroding rains and snows they are much sooner dried again, the north sides receiving sunshine, while the south reposes in shadows. The lowest patches occur at elevations of from three thousand five hundred to five thousand feet above sea level, and thirty to forty miles below- the summits, upon the driest and most enduring portions of vertical walls, where they are protected from the drip sod friction of water; also on hard swelling bosses onthc bottoms of valleys, where they are kept dry by bowlders. In the summit regions, small active glaciers still linger, which present moraines of even' kind in process of formation. Those of the ancient glaciers are clad with forests and extend down through the middle region of the range. In the lower region, polished surfaces are entirely wanting. So also arc moraines, though the material which once composed them is found scattered, washed, crumbled and re-formed over and over again until its glacial origin would scarcely be suspected, unless we trace it back into the undisturbed moraines of the middle region. All of Ike magnificent forests of the Sierra are grousing upon mo- n. N'ATi'KAI. HISTORY. .".1 raine mil, which, as vet. has suffered little change since it was first eroded aud outspread for them by the ancient glaciers. The most impertshaWIe of the glacial phenomena under consideration, are the rn/a-"--. rtilgen and rark iiuvtma.} the Irnt'i.i. shapes and geographical position of which, are specifically glacial. Yet even these are considerably obscured by post-sfiaeial weata- oring, and a growth of forests. The glacial phenomena therefore brighten and become more legible as we ascend to the fresh work of the living glaciers on the summits. Rock and snow avalanches have produced marked changes, but these are very much restricted in their range, aud have done little towards altering the glacial physiognomy even of the localities w here they prevail. On the slow and gentle withdrawal of the iee-mantlo, many a weak tower and impending brow were shattered by the first severe post-glacial earthquake, traces of which are still conspicuous in every sheer walled valley and around the bases of the summit Alps. To this inrlh'jiink'' alone, which occurred at lens! three centuries ago, nine-tenths or more of the cliff taluses are m its stool once in hundreds or thousands of years. This brief survey of the various forces inees antly or occasionally in action, wasting the mountain surface, would at first lead us i- li. NATfKAI. Ills'!" il;l . to siq-p.--.i- thai the total amount of dcgradat ion ;:.,-! be enormous. But on tin' contrary so indestructible no- 'ia- Sierra IJoeks, and so shod i-. ' -e period through which theyhave been exposed to these a-i mis, the general result is eoiitparativ el\ insignificant. '1 :ili.sitet] striated ana-. e.n-i it tit ing -- considi rabie a fxr- I ton of the upper and mi. bib- region, have no! yet been degraded to the bue-hundreilth of an inch. Farther down, measuring tablets abound, bearing the signature of the ice sheet, while the amount of torrent erosion is certainly estimated by measuring tin- depth of their channels below the unchanged glaciated surfaces lining their banks. Still farther down, where the polished surfaces disappear, we have ither valuable data for otir estimates in the height of ;,oi holes drilled into the walls of gorges, and lu the form of the bottoms of the valleys containing these gorges.- Slimming up these results, we find tin- average quantity of postglacial denudation in the upper hall' of tin- ranjje, cinbraeihu a /one twenty-live or thirty miles u i-j,-. ,,-,,,''„-/,.'.;,/ ,,.,- ,,,,, ,.,-,-,,,/ ,, /,,,;!, „f thru iiuhis. That of the lower half has been much greater, probably several feet. Nevertheless i! is certain that the main features have not been radieaily altered. The jihi/sitiguomy of the range from base to summit is strictly glacial, liivcrs have traced shallow wrinkles, avalanches have made sears -upon it, and forests have bearded it. but the change is not greater than a feu years would make upon a human face exposed to winds and storms and the changing atmosphere. The multitudes of lofty mountains, distributed along the summit of the portion of the Sierra under consideration, are almost wholly unexplored. They have been entered hastily a! a few points adjacent to trails, and a few of the snore accessible have been ascended, such as Jits. Dana, l.yeii, Whitney, and Tyndail. while the graiid wilderness of mountains, from whose fastnesses the chief tributaries of the San Joaquin and King's liivers take their rise, has been mapped from a distance without any attempt at detail. Their echoes are never stirred by the hunter's rifle whether Indian or white man, for, excepting tin* wild sheep, there is no game to tempt him even to the lakes ami meadows that lie around their bases, while their glaciers, avalanche-swept aud crevassed, and thin labyrinths of yawning gulfs and crumbling precipices, offer dangers which only the most powerful motives could compel one to dare. 2 The.-e uld strah.jt-.J j et h ►!.-#, ate uitea ;uim-! a huinlreil I'eet ;th";a- the river level*-. v. s \: i i: u. iir-ror.v. Looking southward al umphrev, tie- peaks see iia- range from the ,-ummi! of Sit. r11 .!11. v. tin- peaks -i-i-n: ' in- sown broadcast over a wide area. Scores of them i-xc i thinH-n thousan i. many are fourteen t;i -1— sand lee! high, vel so eloselv a."'' they -.,.! npa- '. i- i Ilia! few rise more than two thousand feci above their -'"-a proper liases. Even this degree of individuality is seldom attained, for they are -!il! further connected by the jag ---i walls that swoop across tin- interspaces from shoulder to shoulder in magninVenl curves. To give effectiveness to any one of them, those adjacent would Feuuirc lo be n-moved. However awe-inspiring and incomprehensible these vasf mountain assemblies seen) to be. i! ommou -in.:in and the facts .-!' 'heir individual history are problems easih solved In the pi!i.-!it student. Beginning with pinnacle-: which are the sriesllcsl of the summit ui umtaiiiots. No geologist "iii claim thai each pinna--'. was formed by sjK-cial upheaval, nor that iia- little chasms which si-j.a- rate them vwi'i- madi' by subsidence. :' iia- rending of ihe rock, fin- many of them are scarcely a fool deep, and may be formed artificially wherever the structure is suitable, simply by the removal of a block or two that has been loosened by the development of cleavage planes. We therefore conclude that pinnacles were formed by the removal of the materials which once filled the intervening chasms. The '/ . -/ .) I'inttiielrg are from one to nearly a thousand feet in height, (heir forms and dimensions being determined not by euta- elysmic fissures but !y orderly joints and eb-avage plain'-.', whVh give rise to leaning form- where the isivi nil pi: .r are im-iisei, as oii tile erc-i of Mi. Kv the mouth of a tributary valley, that conducts to a erater-shajx-d tce-womh. From this womb the ancient tributary glacier emerged, which in thrusting itself into the main -alley trunk caused the depression we are stttdj ing. After maintaining the new trend, thus modified, for aitont a mile an-i a half, the huge valley swerves lightly to tin- right. Again searching for the cause, we discover another ice-grooved tn'lnitaiy valley entering on the Iff}, which likewise conducts back io an ice-womb, whoso glacier in uniting with the main valley trunk deflected it like the fust, as far as its force, modified by the direction, smoothness ami declivity of its channel, enabled it to do. Still lower down, the noble valley has been pushed round in a curve to the left by a series of small tributaries which, of course, entered on the light. 77c Dynamics if tin- Ancient Glaciers are sublimely simple: With each change in direction there is always a corresponding change in depth or width, or both. On Hearing the basin of the Tuolumne .Mer de Glace if. is seen to be swept entirely round ! i the '-vest by powerful ( nnv:;-.-, whkih descended few tbeftanfcs ',' Uu. Dmm, G" ' *. t.)rd ami othrm. Kverv where we see the --aiise delicate eOBSpi ;ia. iaf-$&F®„ and no other; throughout the whole periou ir foptAt'.om the valleys of the Sierra were lithe as serpents d wineeidaflt the touch of every tributary. As to their cmnparatici- size, ve find the. greater ike i basins the greater the imUeya which proceed from them. No such direct and simple relations exist between water currents an-i the valleys in which they flow. Thus the Tenaya basin is not i.ne-fumili the size of 'he South Lyell. yet its valley is meh Itnrger, Indeed some valley- ' mi streams at all, and the topographical conditions of the .t\ demonstrate the impossibility of their ever having had any. as we have already observed, have not eroded the li-.- hundred thousandth pari of the valley- in the iippi i and middle regions. Neither eon id , r- -,-a -. in! streams have i-M rei ed any appreciable influence upon ii.- ir formation, for their trend- ai.- .- ',. /-'ve, eroding backwards into the bases of the peaks and pinnacles, and thus increasing the effi cts of winter snow ava- laneh-s I hat sweep ! heir sides. Notwithstanding the ruinous, crumbling aspects of the summit peaks, they ha\e suffered Very little change since the close of the glacial period, for, if denudation had been rnore extensive, their separating cirques and gorges would he more encumbered with debris; we find only a mere sprinkling of detritus, and that very little material has been removed by jiost-glacial streams is proved by the fact that the small lake basins through which tln-v flow are riot yet filled up. We will briefly consider the formation nf a few special mountain peaks, as -.in illustration of the foregoing principles. The /.'/i .7 Itftftp lies due east from the Yosemite valley at a distance of about sixte.-n miles in a straight course. Large tributaries of the Merced, Tuolumne, Rush and San Joaquin Rivers. take their rise amid its ice and snow. Its geographical importance is augmented by it- having been the centre of dispersal for some of the most influential of the ancient glaciers. LijiV. the dominating mountain of the group, reaches an altitude of thirteen thousand two hundred feet, though it is only a few I'eel higher than adjacent peaks, and all that individually pertains to it is a small fragment less than a thousand feet high, the existence of which is owing to slight advantages of structure and IV. Minni m- ! !:!. ' position, which prevented i' - b.-ing eroded a- fast as the common ma-- of the range. Glacial fountains are rounded in a horizontal direction at the hi ad :' !' the -alia- reason that thev are a' the bottom, this being tin- form which otters greatest re-i-tJinec to glacial erosion. A s'-uu'eirciihir till/line i- thn.s formed, which the glaciers maintain in pushing their way back into the mountain again-! which they heath When !! ciimdUisinshac, !,.,,, pushed quite through th-- axis of the chain --r spurs,.tejftrtite mountains or peaks an ppuluced, the degree of whoso individuality depends upon the extent and \ aria! a m of the en -' n. ay - i - that th snow ,!! t.-il in ii fountain ienlv and ,n b basins should pass through the iit-v,- condition so sn begin to erode at the ven fiead that this is the ease i shown Iy unmistakable I races of such erosion upon the bottoms and sides of wombs now empty. The change of climate which broke up tin- glacial p riod would naturally cause an earlier transformation of su-ov with eroding ice ami produce the present condition of filings as a necessary consequence. The effects of shadotrs in prolonging and intensifying the action of portions of glaciers are shown in moraines, lake luisins, and in the difference in form an-i sculpture between the north and south sides of valleys and mountains, facts which I cannot stop here to present. I; is only to their effects in the segregation of mountain masses thai I would direct particular attention. An exantiiurinn of tin- --\r.-lh-ut d. tailed map at Use Sierra, ftttjamtt to i¥wift}. made suid.-r the auspices of ' Geoloeiesl Survey, wfHsiftiw the diici fioii of extension of the glacial . rtphithcatrc*.--"(key are in a southerly direction, beneath lite protection of phswfcw--cast by peaks and ridges. Again, ii will be seen that because the Merced spur trends in a southerly direction, its western slopes are in shallow in the fo-rentVvtl, ifs eastern in the afternoon : consequently it has a series of .glacial amphitheatres hi-Hi sides, while another ridge trends in an easterly direction and its southerly slopes ire scarcely at all in shadow, consequent ly all its glacial amphitheatres are on the northern slop- The same admirable obedit nee to shad .vs is con- picuons ia parts of the range; the few surviving glaciers are .-ecu follow! them. Glacier- are the onlv eri/ders trhich on- thttg ffocerneil. The Merced -pur, King about ten mih-s to the southeast of the Yosemite \al\-, and almost the same distance from the main axis, presents a ven instructive range of peak- eroded from a single :::::--. Tin- fragments are Ml. (lark, and lied. IShv-k. and Grey Mis. Here we have a range of peaks from eleven thousand live hundred to twelve thousand feet high, blocked out. by the heads of two series of glacier tributaries. The truly magnificent group of granite summits stretching forty miles from Mb Humphreys in a southerly direction is the loftiest of the chain, abounding in elevations of fourteen thousand feet, yet. considered individually, mere pyramids one or two thousand feet high, crowded together and s,-i npon a common base, like pine trees along a ridge. . Ms. Whitney lies io the south of this group, and although the very highest point of the range, geographically or scenieallv has no special significance; viewed from the north or south i! resembles a helmet or the Scotch Cap called Glengarry. Its stimuli! is somewhat flat, curving gently towards the Kern Uiver valley, but holding a bold, precipitous front towards Owen's valhy of Home two thousand feet. These precipices gradually merge into accessible siop.es around from southwest t northwest. Mts. Dana, Humphreys, Kmerson and Ritter far exceed Whitney in grand impress!veness of mass ami outline. A few cold meadow- less hikes nestle around its base, but it possesses no glacier, ami the end of summer finds little snow on its north side, and none at all on the south. Towards the close of the.glacial epoch, the summit of what.is now called Mt. Whitney peered a f'ew hundred feet above a zone of sieve, which fed glaciers that descend towards Owen's valb-y on the east, and Kern on the west. The former cut the eastern face of the mountain, the latter its,southern. western and northern flanks, conferring upon the mountain its special individuality. Instead, therefore, of its being a grand uplift, it is merely a portion of the common mountain mass which, from relative conditions of structure and position has suffered a little less degradation. The same is true of all the mountains under consideration. The difference between the peaks and the passes is not that one tire elevations and the other depressions both an- depressions differing only in degree, the abasement of the one having been clfcctcd at a slower rate are left behind as elevations. 8. NA'Il'iiAI. HI-TO'.iY. 59 l.ifh Bowed above, them. ---. i.-ii-oved summit peaks well marked. Ail weak nice disitp- Aii the mountains of the flanks have -.-u subji continued denudation of the ice slice' Tin- transition from spiky, angular to these overswepl forms :-. exceedingly well tnarkei towers, pinnacles and crumbling angulai surfaces., at pear, leaving only knotty domes and ridge waves as illustrations on the grandest scale of the survival of the - strongest. Because the ice sheet was universal there remains upon ;dl tin- wide flanks of the Sierra not one weak mountain form. Near the upper limits of overflowed mountains there are n exceptions to this rule even in appearance. It is only where we descend to regions longer left bare by the ice. and therefore more weatln red "hat we iin-1 instances of mountain rocks at rtm'i --//. .'a struct* .- ami strong inform. There is now a lock neat' Yosemite which is ready to fall apart by the development of it- K. ;.* W. cleavage planes, yet it is certain that it once stood the strain of Yosemite Creek glacier. If the Sierra were built up of one spo-l.-- of rock homogeneous in structure, then we might have difficulty in finding data upon which to ground our estimates of the quantity of denudation accomplished by the ice sheet and scparaic glaciers in the development of the think mountains. Some portion of the main axis as well as outlying spurs are capped with slates, and, all the base is slatc-covercd. The circumstances connected with their occurrence in these localities furnished proof little short of demonstration that they once covered ail the range; and from their known thickness where they occur, we tn&y approximately estimate 'he quantity remove! where' they are u-:-!:.-- we mm find, but the rich profusion of mountains ami mountainets - marvellously iudiv i'hiali/ed would never have had existence, the whole think would have been platted UAI. IHSTOUY, the rock was in process of formation by the LveJI, Tenava am Hoffman glacier-: residual fragments of thesai Al the slIKUflif we see the cut ci-jc- of c.,r: I iii.-n b i.cen: i e fay crs bit h haw- o. termined the curved outline. A small gable also appears, produced by the development of diagonal cleavage plattes. cul in from bv vertical planes, fin a fragmentary dome, situated on the south side of the Mono Trail, near the base of' Mt. iloifmaii. remnants of concentric shells, from five to ten fee- thick, are .-cell on tin- up-current side. Sections of unremoved siml's are visible. This is an admirable illustration of the mode in which a wide and deep ice current clasps anil denudes a dome, removing one after anot her of its concentric shells while it still maintains its own general form. Tracing the stria- we learn that it has been erode! at once on the front, back and sides. Where the pressure has been greatest, the erosion has lu-eli leas! ftecaiise tin- layers have been pressed against each other, instead of aw;n from one another, as on the sides and back, and could not, therefore, be so easily broken up. The lack of individuality so observable among the summit mountains is chiefly \i\e to the comparatively uniform structure and credibility of the rocks out of which they were developed. Their firms consequently are in a great degree dependent upon the glaciers which have wrought them Hot the strongly structured and specialized mountains and mottntainets oj the Hanks, while accepting the ice currents as developers, still defended themselves from their destructive and form-bestowing effects. In general, the stronger and more specialized the structure -t' any mountain, the greater will be its ability to control the destinies of its own shape. Ia a profounder analysis of the causes of mountain forms we shall come to see that those we have been considering are only proximate, and that neither ice. water nor any other eroding .'cent has done much more than to disinter their buried beauty. Some other force or forces, crystallization perhaps, moulded them while thev vet lay buried in the common mass of the range. In gen- eral the grain of mountains determines their surface forms; the grain of a mountain oak is not more gnarled ami intcrwaved than is the Sierra granite. The ice-sheet is the only evader which works with reference to the grain of mountains on a large scale. B. NA ii ;: it HISTORY. fi.'i The wonderful adaptabilitv ■-:' ice for the development, of buried mountains will be more and more un lerstood as it is studied. (■ rani to crystallizes into landscapes, anil snow crystallizes above them iu bring their beauty to the lig '. lb-re if smooths a pavement by -lipping flat ly over ii ami .-■ . ,,-",,, / it - inequalities tike a common plane. Again it brings out '* ■ -•■ inequalities, gliding over and around the clusters of domes, feeling out every weak spot, sparing the strong, and destroying the feeble—irresistible, yet compliant like the wind. Rocks are brought into horizontal relief on the sides of valleys wherever superior strength of struct;:!,-or advantageous position admits of such development, iu-! a- they are elsewhere in a ver- t ieal direct Ion. Some of these are of a magnitude that well deserves the name of horizontal mountains. Magnificent example- of them are sees in the profound canons of the Merced, Tuolumne and King's Rivers. That {he variability of resistance of the rocks themselves accounts for the variety of those horizontal features, is shown by the prevalence of this law. Where the uniformity of glacidl pressure has not been tUstttrberl /-; th-- entrance of a tributary, ice find that where valleys an tietrr&west the rocks are strongest. In the case of valleys with sloping walls, its salient features are developed in an oblique direction, but neither horizontal nor oblique mountains or mottntainets can ever reach as great dimensions as the vertical, because where a retreating curve is formed ■e r5:c-ives,i.-ss,:iUi etve !Bre, {site 'ftiHirer . Urns uiiug'itaijitftit l:*'l iu a weaker portion of a valley wall, it less pressure, while the salient er\ they project into the 'srt t*j*g \ the irregularity. So intense is the pressure brought t bear si j-- o mie of tsbt.se salient bosses, they are sometimes broken oil* o. he lower -side with a fracture like that produced ia blasting. These 'fractures are the highest expressions of glacial energy I have met. The same tendency toward maintaining evenness of surface obtains to some extent at least, ia the ease of vertical erosion, as where a hard bar extends across the path of a gh.-ier, or an isolated rock rises out of :i comparatively level area exposed to the full sweep of the overpowering en ml. If vertical cleavage be developed in such rucks, moutonuoed if m forms wili result, "ith .-jilit faces turmd u;,y from the direr'ion ■■ th. dote. '1 lies il.- n .am. T r.-.n- - are cveeoiuiiglv aliiiniiani in i n a few inches to over a thousand feel in height. If no cleavage planes arc developed, long ovals will he formed. the denuding whosi gritttesf diameters extend parallel with the on I i lit. In vertical erosion the general tendency is to make the valleys deeper ami ridge- relatively higher. The ice current being constantly attracted to the valleys, causing erosion to go on at an accelerated rate, and withdrawn from the more resisting ridge-. until filially they emerge from the ice-sheei altogether. Thus ii appeals that all the mountains of the range between hit. ::■'- . :■■" and '.','.) . whether the lofty Alps of the summit, the richly sculptured dome clusters of I he Hanks, or tin- burn! bed bosses and mouutaiiiets projecting from th.- sides of valleys all owe their development to the icc-shcel of the great winter, which brooded them all. ami flowed grandly above fhem like a win 1. In all these sublime chapters of Sierra bistort tin re has been no upbuilding, but a gradual dismantling, and of this, all il-- elevations and depressions are the records and monuments. lA|-!.tSOTo\IA (\vi.l!'of;NrA. AS ISSECTIVOKOCS i'F.ANT. IIV W.M. M. Caw. of Wilmington, Del. The Natural Order of Plants Sarrnccniaecn' is composed of but three genera ami eight species. The sis species of Sarraceuia are found native along the Atlantic slope of the United States and principally south of Virginia, one species only extending northward to Newfoundland and thence westward to .Michigan. The single species of Ileliamphora ■ has been found only on a mountain of British (luiana or Venezuela : while the remaining member of the family, the Itarliiujtonia Valifornica of Torrey,- inhabits a few 1 llelith mi in Tr.-iu-. I.iim. -■•-. V-1. I-. j,. i.:, ,-t .,.; 3 " on Hit- Ihirtiifjt'-ui-t Calijurni-rt, :i m-w |.i!i-i .-r j-Imil fr.un Northern CuIiliirti'.H. IJy John 'I\.nvv. F. I. - ■lailU.-m.aii C'uiiti:!.uu--iis. A[uil. |sa;i. f tin- com ' an elevation.'1 of ttotio, to 7000 feet in lie- northern moun* if California bem-ath tin- snows of .Mt. Shasta. The Sarra- having their home in a country long since brought under i i-!' civilized man. have been subject to tin- observas ti-m- of ua'ni.bi-1- fur many year-:. Ve! with [Kiriiaps a single t-M-i ption, the Sarraet-iiio c-iriolnris. the peculiar adaptations and structural arrangements which so admirably serve their purpose a- insect catchers have not been thoroughly studied. Indeed it was no! until Dr. Melliehamp's most interesting and instructive observations on the above-mentioned specie- were made that its operations were fully understood; though Dr. Oray has shown us that manv of the fads connected therewith had long ago beva made public by Dr. McBridc and Mr. Elliott, Having been mm-h interested in researches of '.his character, and fully cognizant of Dr. Melliehamp's exjicriments whin- they were l-eitig carried on.it was vert natural that I should turn (o the nearly related California!! plant, in order to ascertain if possible if it had similar in-eet-previug habits. It was first discovered in !-s|-.' by Dr. Braekenridge of the Wilkes' Exploring Expedition.4 But bis specimens were too scanty and imperfect to warrant a description, and it. was not until ls."il that the late Dr. Torrey received additional ones in a ilowering State. Still two years elapsed before his excellent description and plate were published by the Smithsonian Institution. Kven then ripe seeds had not been obtained, and some years still passed before Dr. Gray's description of them completed the systematic diagnosis, A plant so rare, known only as inhabiting a ft*v-stations lin if- rugged, ahtiost ttalnhaluted and sit tie visited region,' white thus 8Siordig sutffcieni material ' d specimens, and the dcscriptiwis of a single observer of the perfei. i living plant for an investigation of its insect-catching properties, am! what is here offeo•! is not so much to give a thuiough dese iption of it:- ' "iietttre ami fnne- fU, l.cuiiii-. i I'e'- r.'in-y -i/r-i. a. v. x. s. v. win. i: ri-i.ii'. Itrt-tvcr xiy.- He has* aiumi ii . au c-U.-vatii-ii - -i -u.'/p https://scholarlycommons.pacific.edu/jmb/1016/thumbnail.jpg