350 THE HISTORY AND SCOPE OF ZOOLOGY IX 



progressive simplification of structure may have, and 

 in many lines certainly has, taken place, as well as pro- 

 gressive elaboration and continuous maintenance of the 

 status quo. The introduction of this conception neces- 

 sarily has had a most important effect in the attempt 

 to unravel the genealogical affinities of animals. It 

 renders the task a more complicated one ; at the same 

 time it removes some serious difficulties and throws a 

 flood of light on every group of the animal kingdom. 



One result of the introduction of the new concep- 

 tions dating from Darwin has been a healthy reaction 

 from that attitude of mind which led to the regarding 

 of the classes and orders recognised by authoritative 

 zoologists as sacred institutions which were beyond 

 the criticism of ordinary men. That attitude was 

 due to the fact that the groupings so recognised did 

 not profess to be simply the result of scientific reason- 

 ing, but were necessarily regarded as the expressions 

 of the "insight" of some more or less gifted persons 

 into a plan or system which had been arbitrarily 

 chosen by the Creator. Consequently there was a 

 tinge of theological dogmatism about the whole matter. 

 To deny the Linnsean, or later the Cuvierian, classes 

 was very much like denying the Mosaic cosmogony. 

 At the present time systematic Zoology is entirely 

 free from any such prejudices, and the Linnsean taint 

 w^hich is apparent even in Haeckel and Gegenbaur 

 may be considered as finally expunged. 



A classification which expresses the probabilities 

 of genealogical relationships as indicated by the latest 

 results of investigation, is that at which every teacher 



