814 



SCIENCE 



[N. S. Vol. XXVI. No. 676 



Long before it was learned that the bad 

 lands of Nebraska and other parts of the 

 west constituted a veritable mausoleum of 

 mammalian and other vertebrate remains, 

 a fragment of a tooth was submitted to 

 Leidy for examination, who withoxit a mo- 

 ment's hesitation said it was part of a 

 molar of an extinct kind of rhinoceros. 

 The correctness of this determination was 

 questioned when the tooth was brought to 

 the academy, it being almost incredible 

 that a rhinoceros could ever have lived in 

 Nebraska, and further, the academy did 

 not possess at that time the skeleton of a 

 rhinoceros with which to compare the tooth 

 in question. The correctness of Dr. Leidy 's 

 opinion was, however, fully sustained soon 

 afterwards by the discovery of several 

 entire molars with a complete skull of the 

 animal. Dr. Leidy told the speaker that 

 the remaining part of the tooth of which 

 he had examined the fragment was found 

 in situ in the skull, and that the broken 

 fragment adapted itself perfectly to it. 

 "With the revealing of the extinct life of the 

 west Dr. Leidy, whose almost inexhaustive 

 knowledge of the vertebrate skeleton quali- 

 fied him, and at that time him alone, to 

 interpret fossil remains, began at the acad- 

 emy that series of epoch-making researches 

 which, in his hands and those of his succes- 

 sors, established on paleontological evidence 

 the doctrine of evolution so that no one 

 competent to appreciate that evidence has 

 since ever doubted its truth. Indeed, con- 

 sidering the circumstances, the few skele- 

 tons to be found in museums in this country 

 at that time with which the remains of 

 extinct animals could be compared, Leidy 's 

 determination of the tooth just referred to 

 as being that of an extinct rhinoceros was 

 as remarkable and as replete with results 

 as Cuvier's identification of the bones 

 found in the quarries of Mont Martre as 

 being those of an extinct opossum. Indeed 

 as far back as 1853— five years before the 



appearance of Darwin's "Origin of Spe- 

 cies" — Dr. Leidy observed: 



The study of the earth's crust teaches us that 

 very many species of plants and animals became 

 extinct at successive periods, while other races 

 originated to occupy their places. This probably 

 was the result in many cases of a change in ex- 

 terior conditions incompatible with the life of 

 certain species and favorable to the primitive 

 production of others. Living beings did not exist 

 upon earth prior to their indispensable conditions 

 of action, but wherever these have been brought 

 into operation concomitantly the former origin- 

 ated. Of the life present everywhere with its 

 indispensable conditions and coeval in its origin 

 with them what was the immediate cause? It 

 could not have existed upon earth prior to its 

 essential conditions and is it therefore the result 

 of these? There appear to be but trifling steps 

 from the oscillating particle of organic matter 

 to a Bacterium; from this to a Vibrio; thence to 

 a Monas, and so gradually up to the highest 

 orders of life. The most ancient rocks containing 

 remains of living beings indicate the contempo- 

 raneous existence of the more complete as well as 

 the simplest of organic forms; but nevertheless 

 life may have been ushered upon earth through 

 oceans of the lowest types long previously to the 

 deposit of the oldest paleozoic rocks as known 

 to us. 



Where, may it be asked, can there be 

 found in the whole range of biological lit- 

 erature a more concise statement in regard 

 to the origin of life, the extinction of spe- 

 cies, the survival of the fittest — in a word, 

 of Darwinism?^ Again, in regard to the 

 descent of man, Leidy suggested:* 



That but little change would be necessary to 

 evolve from the jaw and teeth of Notharctus that 

 of a modem monkey. That same condition that 

 would lead to the suppression of a first premolar 

 in continuance would reduce the fangs of the 

 other premolars to a single one. This change 

 with a concomitant shortening and increase of 

 depth of the jaw would give the character of a 

 living Cebus. A further reduction of a single 

 premolar would give rise to the condition of the 

 jaw in the old world apes and man. 



As a fitting recognition of Dr. Leidy 's 



' Smithsonian Contributions, 1853. 



• " Bxtinct Vertebrate Fauna," 1873, p. 90. 



