Apkil 18, 1919] 



SCIENCE 



379 



original surface there was found the principal 

 part of the skeleton, considerably scattered 

 about, but with the skull nearly intact and 

 with unbroken tusks. Tlie bones lay on a bed 

 of clay, broken slate, gravel and water-worn 

 pebbles. This was probeil to a depth of ten 

 feet without finding bottom. The right fore 

 leg of the skeleton was missing, but was later 

 found in another potliole 60 feet farther up 

 stream and at least 25 feet higher. Hall 

 thought that the potholes were of glacial or 

 preglacial origin, but I am assured by Pro- 

 fessor Fairchild that they have been drilled 

 since the Wisconsin ice sheet abandoned that 

 vicinit>'. When the ice began to withdraw, 

 the region was depressed about 3.50 feet below 

 its present level, as a result of which the site 

 of Cohoes was covered with a thick deposit 

 of sand and clay. As the land slowly emerged, 

 the old Mohawk River (Fairchild's Iromo- 

 hawk) cut through the estuar.v deposits and 

 finally reached the underlying Hudson slates. 

 Then under the action of strong currents the 

 drilling of the jKDtholes began. The land had 

 then risen, as Professor Fairchild isTites, at 

 least 150 feet. At the same time the stream 

 bed was being worn down into the rock and 

 the falls were moving up stream past the 

 potholes. When the mastodon entered the 

 pothole this had long before ceased being cut; 

 for, as already stated, it had became filled to 

 a depth of at least 10 feet with rock debris. 

 It had quite certainly been abandoned by the 

 river waters, except at times of flood. How 

 now did the mastodon get into that hole? 

 Hall concluded that it had been frozen up in 

 the glacial ice and had been dropped part in 

 one pothole, part in the other. But when 

 those potholes were ready for occupation as a 

 tomb for the mastodon, there was no part of 

 the general glacial sheet from which the 

 cadaver could have reached Cohoes. As a 

 recently dead body it might indeed have been 

 floated down the Mohawk; but the animal 

 could as well have lived and died at Cohoes. 

 We may fairly assume that it had only re- 

 cently died and was lying on the flood plain 

 not far above the potholes. No disarticulated 



bones could ever have been distributed as this 

 skeleton was. The bones must, perhaps with- 

 out exception, have been held together by the 

 ligaments and probably much of the flesh re- 

 mained. At this moment the river rose and 

 swept the flood plain, carrying the cadaver 

 over the potholes. First the right leg became 

 detached and was swept into the upper one of 

 the two holes ; then the remainder of the body 

 was carried on and dropped into the second 

 hole. Here the swirling waters either at once 

 or during subsequent floods scattered the 

 skeleton somewhat. As time went on, all sorts 

 of materials were borne into the potholes 

 during freshets. Possibly some trees growing 

 on their margins fell into them. At any rate, 

 they finally became filled up. 



It appears quite certain that when the 

 Cohoes mastodon was buried the deposition of 

 marine sediments in the Champlain and the 

 upper St. Lawrence valleys had largely taken 

 place and the Champlain epoch, about the 

 last leaf of the last chapter of the Pleistocene, 

 had nearly ended. Did mastodons end their 

 career at this stage of geological history or 

 did they continue on into the Recent epoch? 

 It may be impossible to determine this. If 

 they did continue to exist, it might be sup- 

 posed that remains of them might be found 

 in deposits of marl and muck overlying the 

 Champlain deposits along Lake Champlain, 

 and the St. Lawrence and Ottawa rivers; but 

 the writer has not learned of any such cases. 

 At any rate, the close of the Pleistocene or 

 the beginning of the Recent became an in- 

 salubrious time for this species, a mighty race 

 which can be traced back possibly to the 

 Pliocene and which had weathered the vicissi- 

 tudes of four or five glacial periods. At ap- 

 proximatel.v the same time there perished two 

 species of elephants, the giant beaver (Casto- 

 roides), the moose (Cervalces), and perhaps 

 other great animals. O. P. Hay 



TJ. 8. National Museum 



HUMAN FLYING 



To THE Editor of Sciekce: While engaged 

 in some scientific research, my attention was 



