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THE POPULAR SCIENCE MONTHLY. 



ers, particularly with those which have be- 

 come nomadic, it has been cultivated to 

 a high degree of development. The signs 

 have their birth, growth, development, 

 changes, and death, and those which are 

 in general use must be of great antiquity. 

 Colonel Mallory's researches during several 

 years showed a surprising number of signs 

 for the same ideas which were substantially 

 identical, not only among savage tribes, but 

 among all peoples that used gesture-signs 

 with any freedom. Indians who have been 

 brought to the Eastern States have often 

 had happy intercourse by signs with white 

 deaf-mutes ; many of their signs were iden- 

 tical, and all sooner or later were mutually 

 understood. The so-called sign-language of 

 the Indians is not, properly speaking, one 

 language, but it and the gesture systems of 

 deaf-mutes and all people together consti- 

 tute one language the gesture-speech of 

 mankind of which each system is a dia- 

 lect. Colonel Mallory next showed how this 

 language of gestures aided archaeological re- 

 search. The Indian signs, as well as their 

 myths and customs, form a part of the pale- 

 ontology of humanity, to be studied in the 

 history of the latter, as the geologist, with 

 similar object, studies all the strata of the 

 physical world. 



The Origin of Lake Erie. In a paper, 

 read at the recent Cincinnati meeting, on 

 the evidence from the drift of Ohio in re- 

 gard to the origin of Lake Erie, Professor 

 E. W. Claypole endeavored to show that 

 the theory that the lake-bed was excavated 

 by local glaciers at the oncoming and pass- 

 ing away of the ice age was not competent 

 to account for the depth of the basin. A 

 careful examination of the drift of Ohio in 

 various parts of the State had convinced 

 the author that the average depth of the 

 erosion performed by the great continental 

 glacier did not exceed fifty-six feet. If this 

 was the limit of the effect produced by this 

 immense mass of ice during its whole dura- 

 tion, it was idle to ascribe to a small local 

 glacier the removal of many hundred feet 

 deep of rock which was involved in the 

 excavation of the bed of Lake Eric. More- 

 over, if the lake-basin had been so formed, 

 the material taken out would have been 

 found piled up like a mountain around the 



southwest end of the lake, but it is not so 

 found, and the drift in that region is not 

 perceptibly deeper than in other places. 

 Furthermore, no local glaciers could have 

 been formed unless the lake-beds had pre- 

 viously existed in their present form and 

 size, and to ascribe the beds to the action of 

 such a glacier is to mistake cause for effect. 

 Observations of the drift in Indiana and 

 Illinois go to confirm this view. The gla- 

 cial theory being held to be untenable, the 

 only alternative is to ascribe the formation 

 of the lake-bed to the action of an ancient 

 pre-glacial river, to which Lakes Erie and 

 Ontario would be a broad, open valley, 

 worn out where the rocks were soft, and 

 connected by deep channels where they were 

 hard, and this river he proposed to call the 

 Ontario River. Mr. Holley replied to Pro- 

 fessor Claypole's arguments, by exhibiting 

 sections of the lakes and' their rivers, and 

 pointing to the fact in respect to the Niag- 

 ara River, unique among American rivers, 

 that while the descent of the river is in one 

 direction the rise of its banks is in an oppo- 

 site direction; the elevation anciently formed 

 a dam which set the waters back to Lake 

 Michigan, causing the constitution of an im- 

 mense inland lake, which emptied its waters 

 through the Illinois and Mississippi Rivers. 

 In this theory, Professor Claypole might 

 find a way to get rid of his drift. 



Ancient and Modern Shells. Professor 

 E. S. Morse presented at the last meeting of 

 the American Association some observations 

 on changes of form which shells of the gen- 

 era My a and Lunatia seem to have under- 

 gone since the New England shell-heaps 

 were deposited. This had been ascertained 

 by comparing the shells of the ancient de- 

 posits and living shells of the same species, 

 in New England and Japan, where similar 

 changes were found to have taken place. 

 It appeared, from measurements that he had 

 made of the common clam (My a), at Goose 

 Island, Maine, and at Ipswich and Marble- 

 head, Massachusetts, that the ancient speci- 

 mens were higher in proportion to their 

 length than the recent specimens. A com- 

 parison of the common beach -cockle (Lu- 

 natia) from the shell-heaps of Marblehead, 

 Massachusetts, showed that the present form 

 living on the shore to-day had a more de- 



