504 THE HISTORY OF BIOLOGY 



middle-forms and archetypes, letting the scientific material that actually 

 exists speak for itself. His method thus acquires a soundness that has given 

 to his results a lasting value. He died in 1910. 



Hubrecht on phytogeny 

 Gegenbaur had a far more imaginative disciple in the person of the Dutch- 

 man A. A. W. Hubrecht (1853-1915), a professor at Utrecht. In his younger 

 days he was occupied mostly with the invertebrates, especially the worms, 

 but he afterwards devoted himself entirely to the evolution of the Mam- 

 malia. In this field he made valuable contributions by collecting material 

 in the course of expeditions in tropical countries and by investigating, with 

 special reference to their embryonic development, a large number of rare and 

 little-known animal forms. On the basis of this material he speculates deeply 

 upon the origin of the Vertebrata from lower animal forms, producing a 

 number of theories , that diverge considerably from what the earlier evolu- 

 tionists regarded as indisputable truth. The sharks, for instance, he places 

 for palasontological reasons in an isolated position in the system — that is 

 to say, in direct opposition to Gegenbaur's view — one of many proofs of 

 how fresh facts in this sphere have produced fresh difficulties, which it has 

 not been possible to solve with uniform results. 



A complete account of the works produced by the pupils of Gegenbaur 

 or in his spirit would fill a volume; even in modern times comparative anat- 

 omy is largely under the influence of his method. Pupils had flocked to his 

 laboratory from all parts of the world. In the following chapter will also 

 be mentioned some pupils of Gegenbaur, who in their younger days followed 

 in his footsteps, but in later years struck out new paths of their own, some- 

 times with brilliant success. 



Even the man who was in closest touch with Gegenbaur in his best 

 days and who exercised most influence on him, just as he was most in- 

 fluenced by him, went his ov/n way towards the end; this was Haeckel, a 

 man who gave to Darwinism a peculiar stamp, extremely characteristic of 

 the age, and who contributed much to its success, though perhaps still more 

 to bringing it into discredit. 



