6 THE ART OF MORPHOLOGY 



along the same general lines though with differ- 

 ent perspectives and methods, the one exer- 

 cising a profound substantive influence upon 

 his day and generation, and occasioning a great 

 public disputation, the personal influence being 

 permanent, the public disputation ending in 

 platitudes ; the other, in the quietude of the 

 sanctuary, unseen and unknown except to a few 

 intimates, pursuing far-reaching numerical re- 

 searches which have been rescued from oblivion 

 years after their good author had been laid to 

 rest, secure alike from excommunication and 

 from hair-splitting controversy. Students of 

 practical questions of heredity confess to the 

 hope that their investigations may lead to the 

 regeneration not only of cultivated and domesti- 

 cated races of plants and animals but also of the 

 human race, by the selection and perpetuation of 

 desirable characters and the weeding out of un- 

 desirables. From this point of view their work 

 has undoubtedly a direct economic significance. 



In the same way as benefiting humanity, the 

 discoveries in protozoology and parasitology 

 which have rendered the infancy of this century 

 so illustrious, of the relations of protozoa to 

 certain epidemic and epizootic diseases, the life- 

 histories and nuclear changes of the parasites, 

 and their transmission by intermediate hosts ; 

 as well as such discoveries as that of the 

 conveyance of plague bacilli by rat-fleas, of the 



