248 THE DOCTRINE OF DESCENT. 



XI. 



The Pediyee of Vertebrate Animals. 



THE final result towards which the doctrine of Descent 

 directs its efforts, is the pedigree of organisms. To 

 work it out is to collect the almost inconceivable pro- 

 fusion of facts accumulated in the course of about a 

 century by descriptive botany and zoology, including 

 comparative anatomy and the history of development, 

 and to submit the existing special hypotheses to a minute 

 scrutiny and renewed verification. We have therefore 

 claimed in behalf of the doctrine of Derivation the 

 privilege on which the progress of science generally 

 relies that of investigating according to determined 

 points of view, and accepting probabilities as truth in 

 the garb of scientific conjecture or hypothesis. It is 

 manifest that when the doctrine of Descent first made 

 its appearance with the arguments proposed by Darwin, 

 it was only possible to indicate the most general outlines 

 of this great pedigree, which it was the special task of 

 the new direction of science to demonstrate in all its 

 details. But however and wherever specific research 

 was attempted, either the results contributed the form 

 of some part of the great pedigree, or there was, from 

 the first, reason to pre-suppose certain kinships, and the 



