88 



considerable fragment of the whole, it is incon 

 ceivable that any theory of a necessarily pro 

 gressive development can stand, for the nu 

 merous orders and families cited afford no trace 

 of such a process." 



Professor Huxley concludes his investiga 

 tions on this subject by the query: "What, 

 then, does an impartial survey of the positively 

 ascertained truth of paleontology testify in re 

 lation to the common doctrines of progressive 

 modification which suppose that modification 

 to have taken place by a necessary progress 

 from more or less embryonic forms, or from 

 more to less generalized types (Father Was- 

 mann's theory) within the limits of the period 

 represented by the fossiliferous rocks ?" 



And his answer is : "It negatives those doc 

 trines ; for it either shows no evidence of any 

 such modification or shows it to have been 

 very slight ; and as to the nature of that modi 

 fication, it yields no evidence whatsoever that 

 the earlier members of any long-continued 

 group were more generalized than the later 

 ones." Huxley's conclusion has never been 

 disputed, but is the accepted doctrine of the 



