ers, particularly with those which have become 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 identical, 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 constitute one language—the gesture-speech of mankind—of which each system is a dialect. Colonel Mallory next showed how this language of gestures aided archaeological research. The Indian signs, as well as their myths and customs, form a part of the paleontology 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 regard 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 passing 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 duration, 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. Moreover, 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 previously 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 glacial 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 Professor Claypole's arguments, by exhibiting sections of the lakes and' their rivers, and pointing to the fact in respect to the Niagara River, unique among American rivers, that while the descent of the river is in one direction the rise of its banks is in an opposite direction; the elevation anciently formed a dam which set the waters back to Lake Michigan, causing the constitution of an immense 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 genera Mya and Lunatia seem to have undergone since the New England shell-heaps were deposited. This had been ascertained by comparing the shells of the ancient deposits 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 (Mya), at Goose Island, Maine, and at Ipswich and Marblehead, Massachusetts, that the ancient specimens were higher in proportion to their length than the recent specimens. A comparison of the common beach-cockle (Lunatia) from the shell-heaps of Marblehead, Massachusetts, showed that the present form living on the shore to-day had a more de-
