FOSSIL PEDIGREES 95 



meaning clear. A series of fresh-water strata occur in India 

 known as the Siwahk beds. The formation in question was 

 originally classed as Miocene. Later on, however, as a result, 

 presumably, of the embarrassing discovery of the genus Equus 

 among the fossils of the Upper Siwalik beds, Wm. Blanford 

 saw fit to mend matters by distinguishing the Upper, from 

 the Lower, beds and assigning the former (which contain fos- 

 sil horses) to the Pliocene period. The title Miocene being 

 restricted by this ingenious step to beds destitute of equine 

 remains, namely the Nahun, or Lower Siwalik, deposits, all 

 danger of the horse proving to be older than his ancestors 

 was happily averted. A mere shifting of the conventional 

 labels, apparently, was amply sufficient to render groundless 

 the fear, to which Professor A. Sedgwick had given expression 

 in the following terms: "The genus Equus appears in the 

 upper Siwalik beds, which have been ascribed to the Miocene 

 age. ... If Equus really existed in the Upper Miocene, it 

 was antecedent to some of its supposed ancestors." ("Stu- 

 dents' Textbook of Zoology," p. 599.) Evidently, the Horse 

 must reconcile himself perforce to the pedi^ee assigned to 

 him by the American Museum of Natural History; for he is 

 to be given but scant opportunity of escaping it. This classic 

 genealogy has already entailed far too great an expenditure 

 of time, money and erudition to permit of any reconsidera- 

 tion; and should it chance, in the ironic perversity of things, 

 that the Horse has been so inconsiderate as to leave indubi- 

 table traces of himself in any formation earlier than the 

 Pliocene, it goes without saying that the formation in question 

 will at once be dated ahead, in order to secure for the "an- 

 cestors" that priority which is their due. An elastic criterion 

 like the index fossil is admirably adapted for readjustments 

 of this sort, and the evolutionist who uses it need never fear 

 defeat. The game he plays can never be a losing one, because 

 he gives no other terms than: Heads I win, tails you lose. 



In setting forth the foregoing difficulties, we have purposely 

 refrained from challenging the cardinal dogma of orthodox 



