An Introduction to a Biology 



much as it is an embodiment of the recognition by medical 

 men that they depend ultimately for a precise knowledge of 

 nature on the professional biologist who may or may not, 

 at the same time, be a medical man. 



The book should be welcomed by doctors as contain- 

 ing in the earlier chapters a straightforward, though rather 

 brief, account of theories of organic evolution, and by 

 biologists as giving a very full account of the medical aspects 

 of these problems, and by both as an interesting collec- 

 tion, under the title of " The Principles of Heredity," of 

 a mass of information and ideas connected with that 

 phenomenon. 



The reader may object to the antithesis between medi- 

 cine and biology ; but will, we hope, withdraw his objection 

 when it is explained that all that is meant by it is the anti- 

 thesis between applied and pure biology. The recognition 

 by medical men of the value to them of the information 

 with which the biologist is able to supply them is unques- 

 tionably a good thing ; yet it is a curious illustration of 

 the fact that a new movement of opinion cannot stand 

 isolated and alone, cannot be without consequences of one 

 kind or another, that one result of the popularity of the 

 entente between the doctor and the biologist may prove 

 harmful to biology, and through it perhaps ultimately to 

 medicine. 



The danger is that the biologist pure and simple, the 

 man who works at his subject for the mere joy of investiga- 

 tion and discovery, may cease to exist. So many workers 

 of this type are becoming applied biologists, whether they 

 be sporozoologists devoting themselves to malaria, students 

 of heredity to eugenics, or cytologists to cancer. We do 

 not, of course, complain of the application of biological 

 knowledge ; it is obviously fitting and right that as much 

 use should be made of it as possible. But we do complain 

 loudly of the opinion that the application of such know- 

 ledge is, or should be, the ultimate goal of him who acquires 



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