240 GEOEGE JOHN EOMANES 1888- 



few years hence they will wonder why they raised 

 such an ado over the no less obvious principle of 

 physiological selection. 



Yours very truly, 



Gr. J. Romanes. 



He writes to his brother : 



18 Cornwall Terrace, Eegent's Park, N.W. : Simday. 



My dearest James, — This theory, of the Non- 

 Inheritance of Acquired Characters, is that nothing 

 that can happen in the lifetime of the individual 

 exercises any influence on its progeny; effects of use 

 or disuse, for example, cannot be inherited, nor, there- 

 fore, can any adaptation to external conditions which 

 are brought about in individual organisms. Natural 

 selection thus can only operate in spontaneous varia- 

 tions of germ-plasm, choosing those variations which, 

 when ' writ large ' in the resulting organisms, are best 

 suited to survive and transmit. 



This is the most important question that has been 

 raised in biology since I can remember, and one 

 proof of an inherited mutilation would settle the 

 matter against Weismann's theory. I am therefore 

 also trjdng the mutilation of caterpillars at the Zoo, 

 in the hope that a mutilation during what is ^drtually 

 an embryonic period of life will be most hkely to be 

 transmitted, seeing that congenital variations are so 

 readily transmissible, and that these are changes of 

 a pre-embryonic kind. 



All well and with much love, yours ever, 



George. 



