248 THE DOCTRINE OF DESCENT. 



XI. 



The Pedigree 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 zoologfy, 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 priv- 

 ilege 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 di- 

 rection 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 conjecture was 



