THE WONDERS OF LIFE 



tion of the type of physical experiments; the biological 

 conditions are generally too complicated and offer too 

 many weak points to rigorous criticism. The beautiful 

 experiments of Standfuss and C. Fisher (Zurich) have 

 shown that changes in the environment (such as tempera- 

 ture or food) can cause striking modifications that 

 are transmitted to offspring. In any case, there are 

 plenty of luminous proofs of progressive heredity in the 

 vast arsenal of morphology, comparative anatomy, and 

 ontogeny. 



Comparative anatomy affords a number of most 

 valuable arguments for other phylogenetic questions as 

 well as progressive heredity; and the same may be said 

 of comparative anatomy and comparative ontogeny. I 

 have collected and illustrated a good many of these 

 proofs in the new edition of my Anthropogeny. However, 

 in order to understand and appreciate them aright, the 

 reader must have some acquaintance with the methods of 

 critical comparison. This means not only an extensive 

 knowledge of anatomy, ontogeny, and classification, but 

 also practice in morphological thinking and reasoning. 

 Many of our modern biologists lack these qualifications, 

 especially those "exact" observers who erroneously 

 imagine they can understand vast groups of phenom- 

 ena by accurate description of detailed microscopic 

 structures, etc. Many distinguished cytologists, histol- 

 ogists, and embryologists have completely lost the 

 larger view of their work by absorption in these details. 

 They even reject some of the fundamental ideas of com- 

 parative anatomy, such as the distinction between 

 homology and analogy; Wilhelm His, for instance, de- 

 clared that these ' ' academic ideas ' ' are ' ' unreliable tools . ' ' 

 On the other hand, physiological experiments ought to 

 contribute to the solution of morphological problems, 

 and of these they can say nothing. To show the in- 

 calculable value of comparative anatomy for phylogeny, 



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