222 



SCIENCE 



[YOL. YI., No. 136. 



explained by the consideration, that, when the great 

 ice sheet was most extended, its local depth was great 

 as compared to the height of the mountain ridges, 

 and it traversed them obliquely with little or no de- 

 flection; but, as its extent and depth diminished, it 

 yielded more and more to the control of the topog- 

 raphy. Prof. E. W. Claypole pointed out, that, 

 granting this explanation, a strong argument was 

 afforded against the theory that ice is a great agent 

 of erosion. If the erosion of the later epoch was too 

 feeble to efface the scratches left by the earlier, we 

 cannot reasonably regard the earlier erosion as great. 

 Mr. William McAdams, who last year exhibited 

 bones from the loess at Alton, 111., announced 

 further discoveries of the same nature, and described 

 the superficial deposits of the region. The list of 

 species now includes mastodon, ox, deer, megalonyx, 

 beaver of several species, gopher, ground-hog, bear, 

 and an animal allied to the wolf. 



A phase of post-glacial geology was treated by Mr. 

 G. K. Gilbert, who has recently traced an old shore- 

 line of Lake Ontario half way about its basin. From 

 Hamilton, Can., to Sodus, N.T., it runs parallel to 

 the modern shore. It then turns southward, and 

 deviously outlines a great bay, studded with islands, 

 which occupied the basin of the Oswego River and its 

 branches from Lyons to Rome, and sent a narrow arm 

 to Cayuga Lake. East of Lake Ontario it is once more 

 parallel to the modern shore. The outlet was then 

 at Rome, and the discharge flowed down the Mohawk 

 valley. The plane of the old water-surface is no 

 longer horizontal, but inclines southward, with an av- 

 erage slope of about four feet to the mile, and west- 

 ward more gently. At Adams Centre, in Jefferson 

 county, it is 650' above tide ; on the north shore of 

 Oneida Lake, 480'; along the Erie canal south of 

 the lake, 430'; near Rochester, 423'; at Hamilton, 

 350'. It passes beneath the water of Cayuga Lake 

 near its north end. Subsequent to the epoch of this 

 shore-line, the water-surface of Lake Ontario was 

 depressed below its present, as is shown by many of 

 its bays, which occupy valleys wrought by post-gla- 

 cial stream erosion. Mr. Gilbert's working hypothe- 

 sis is, that the shore-mark associated with the Rome 

 outlet records an epoch in which the retreating ice- 

 sheet still occupied the St. Lawrence valley. The 

 northern side of the basin was then relatively de- 

 pressed ; and when the water finally escaped past the 

 ice at the north-east margin of the basin, its sur- 

 face rapidly fell to a position below the present shore. 

 The existing system of levels has been effected by 

 subsequent crust movements. 



A paper by Prof. Frederick D. Chester, on the gab- 

 bros and amphibolites of Delaware, was read by title, 

 and will be published in the proceedings. Prof. A. 

 R. Crandall gave an account of some small volcanic 

 dikes, recently discovered in Elliot county, Ken- 

 tucky. The surrounding strata lie nearly level, and 

 the locality is about ninety miles north-west of the 

 nearest Appalachian dislocation. The dikes do not 

 impress their form on the topography, but have 

 yielded to decay along with the enclosing carbonifer- 

 ous strata. Prof. L. E. Hicks remarked that he had 



observed on the White River in Nebraska a dike 

 which resembles these, in that it is associated with no 

 disturbance of the sedimentary rocks. 



Mr. George F. Kunz briefly described a new mass 

 of meteoric iron from Carlestown, W.Ya., and read 

 a series of notes on minerals from new localities, or 

 otherwise interesting. Among them were native an- 

 timony from Prince William, N". B. ; tourmaline from 

 Rumford, Me. ; a pseudomorph of felspar after leu- 

 cite (?) from Magnet Cove, Ark.; a curious form of 

 beryl from Auburn, Me. ; a capped garnet from Ray- 

 mond in the same state ; and a turquoise from New 

 Mexico, artificially stained to produce a favorite blue 

 shade. He described, also, a collection of rough dia- 

 monds, temporarily in the possession of Messrs. Tif- 

 fany & Co., bringing out especially the fact, that the 

 convex curves of some rough diamonds are not refer- 

 able to attrition, since only the diamond can wear 

 the diamond, but are made up of crystalline facets. 

 A paper by Dr. T. Sterry Hunt, on the apatite de- 

 posits of the Laurentian rocks, was read by abstract. 



EDUCATIONAL MUSEUMS OF VERTE- 

 BRATES.^ 



From what is known of man's present constitu- 

 tion and environment, and from what is commonly 

 believed respecting his future form, condition, and 

 associates, it seems to follow that all kinds and de- 

 grees of zoological instruction, whether anatomical, 

 histological, physiological, pathological, psychologi- 

 cal, or religious, should be based upon some knowl- 

 edge of vertebrated animals. As aiding to make this 

 knowledge real and lasting, every educational insti- 

 tution, of whatever grade, should have a vertebrate 

 museum. 



From many vertebrate collections the average vis- 

 itor carries away, besides the sense of fatigue, certain 

 impressions which are inadequate or erroneous, or, if 

 correct, uncomplimentary. 



The following plans and methods are followed in 

 a preliminary re-arrangement of the vertebrate col- 

 lections at Cornell university: The exhibition-cases 

 should contain only specimens which can instruct or 

 interest the visitor. Not only should facts be dis- 

 played, but fundamental principles should be illus- 

 trated. There should not only be special series of 

 embryos, brains, hearts, etc., but such preparations 

 should be associated, to a certain extent, with the ani- 

 mals to which they belong. Preparations illustrating 

 important facts should retain so much of the entire 

 animal as may facilitate recognition and association; 

 when this is inconvenient, the preparation may be 

 accompanied by a figure of the animal. When the 

 relative rank of several forms is well determined, 

 the lower or more generalized should be placed be- 

 low or at the left, and the higher or more specialized 



1 Abstract of an address delivered before tbe section of biology 

 of the American association for the advancement of science, at 

 Ann Arbor, Aug. 26, by Dr. Burt G-, Wilder of Cornell uni- 

 versity, vice-president of the section. 



