CCXIV 



with the older Loess deposit; and the bones of mastodon, elephant, and 

 other extinct species of mammalia, are so abundant in this deposit, not only 

 in Nebraska, but in other parts of the Mississippi Valley, that no doubt 

 can remain that these animals were also contemporary with the Loess. 



In the instances reported by the late Dr. Koch (Trans. St. Louis Acad, 

 of Sci. vol. I. pp. 6i & 117) of arrow-heads found together with the bones 

 of mastodon, one in the alluvial bottom of the Pommes de Terre River in 

 Benton Co., Mo., and the other in the bottom land of the Bourbeuse River 

 in Gasconade Co., Mo., it was possible to explain the facts stated by him 

 as being the result of more recent changes in the local alluvial drift of the 

 river valley. Dr. Wislizenus (ibid. p. 168) endeavored to account for 

 all the phenomena in this way, and, in the latter case, by supposing that 

 Indian fires had been built over the spot at a time long subsequent to the 

 deposit of the bones, and the whole afterwards covered by alluvial over- 

 flows. He was well acquainted with Dr. Koch, and did not question the 

 veracity of his statements. Judge Holmes had himself assisted Dr. Koch 

 in putting his article into shape for publication in the Transactions, and 

 questioned him minutely as to the particulars stated, and could certify that 

 the circumstances mentioned were positively asserted by him to be true. 

 Nor had he any reason for doubting the truthfulness of Dr. Koch. As lately 

 suggested by Prof. J. D. Dana, it is true that Dr. Koch was not a thoroughly 

 scientific and practical geologist, and he gave some scope, perhaps, to his 

 imagination in the matter of theorizing upon his facts; but he had had 

 some experience in such things, and might be allowed to be capable of 

 observing the facts which he stated, however incompetent to apply the 

 requisite tests for a certain conclusion. But the facts observed and reported 

 were not absolutely conclusiveof the matter, though carrying much weight 

 of probability. 



In this new discovery in Nebraska, we have facts well ascertained by a 

 competent observer ; they are not open to the same kind of explanation ; 

 and they seem to aftbrd the necessary confirmation of the supposed con- 

 temporaneity of man and the mastodon and elephant in this valley. 



Dr. Geo. Engelmann gave some results of his observations on 

 the vernation of American Oaks. He had observed great differ- 

 ences in the vernation of different species, some having condupli- 

 cate, and others revolute foldings ; again, in others the budding 

 leaves are concave or convex, or (at least in one species) inflexed. 

 But the vernation does not seem to furnish distinguishing charac- 

 ters between the two principal sections, the White and Black Oaks. 



J. A. Dacus, Geo. W. Letterman, and Dr. G. Hambach were 

 elected Associate Members. 



The name of Dr. Samuel Aughey was proposed for correspond- 

 ing membership, and that of A. L. Whitley for associate mem- 

 bership. 



