Geological Gleanings. 129 



"The collections contain remains of the horse, ox, sheep, hog 

 and dog, which I feel strongly persuaded, with the exception of 

 many of those of the first-mentioned animal, are of recent date, 

 and have become mingled with the true fossils of the post-pleio- 

 cene and eocene formations, where these have been exposed on the 

 banks of the Ashley river and its tributaries. In regard to the 

 remains of the horse, from the facts stated in the accounts given 

 of them in the succeeding pages, I think it will be conceded that 

 this animal inhabited the United States during the post-pleiocene 

 period, contemporarily with the mastodon, megalonyx, and the 

 great broad-fronted bison." 



In the subsequewt part of his paper, Prof. Leidy proceeds to 

 state the grounds on what he distinguishes the modern horse 

 from the really extinct species, which with its allies of the genus 

 Hipparion, did certainly inhabit post-pleiocene America, but had 

 become extinct before its colonization by man — a very remarka- 

 ble fact to which the researches of Prof. Holmes have added far- 

 ther confirmation. 



Prof. Holmes, dissenting from Dr. Leidy's view as to the recent 

 origin of the bones of the sheep, hog, dog, ox, and common horse 

 found with the undoubted fossils, proceeds to state his reasons for 

 believing them to be post-pleiocene. He attempts to show that 

 some of the bones are scarcely better preserved than those of ex- 

 tinct animals found with them, and argues from the state of pre- 

 servation of shells, and the per centage of these known to be re- 

 cent, as well as the fact of some species still existing in a wild 

 state in America, having left their bones in these deposits. These 

 arguments, however, afford merely presumptive proof, and are 

 liable to many solid objections ; and he does not attempt to show, 

 what alone could establish his position, that the disputed bones 

 have actually been found in undisturbed tertiary beds. Since, 

 therefore, the evidence fails in this essential point, we cannot ac- 

 cept the conclusions of Prof. Holmes; but must believe this to be 

 one of these cases, rather numerous in the history of American 

 tertiary geology, in which comparatively modern relics have been 

 mixed with those of more ancient date. We were somewhat sur- 

 prised to find in the end of the paper a letter from Prof. Agassiz, 

 in which that eminent naturalist appears fully to endorse its con- 

 clusions. Comparing the confident tone of this letter with the 

 evident weakness of the case as stated by Prof. Holmes, it is 

 scarcely possible to avoid the inference that the great zoologist is 



