The Inlieritance of Acquired Characters 25 



production of ev^oluliouary change by the action of the 

 environment on the germ plasm than hy any of the 

 other methods." 



This behavior on the part of some of the lower organ- 

 isms, difficult to interpret without the assumi)tion of 

 inheritance of acquired characters, fostered the following 

 belief. In higher animals, where germ plasm and body 

 plasm are sharply differentiated, inheritance of acquired 

 characters is an impossibility; in the simpler organisms, 

 however, germ and body plasm are doubtless one and the 

 same thing, with the result that a certain amount of 

 inheritance of acquired characters can and does take 

 place. Such an opinion would not be out of harmony 

 with the views of Weismann, who was early forced to the 

 belief that inheritance of acquired characters must take 

 place in the more primitive organisms. 



The opinion of the biological world was becoming 

 fairly well settled on this matter when Guyer's startling 

 results (9) were published. It will be seen that Guyer's 

 methods ''strike at the germ plasm" more directly than 

 any that had previously been tried. 



Grinding up the eyes of white rabbits, Guyer pro- 

 cured a lens-extract. This was injected into the blood 

 stream of fowls. There, since the lens-extract was a 

 foreign and " inhamionious " protein, a reaction took 

 place which resulted in the production in the blood 

 stream of an antibody (following the same principles 

 which apply to the production of antitoxins in medicine). 

 This particular antibody had the peculiar property of 

 "precipitating" or in some way rendering functionless 

 the characteristic protein of rabbit lens. The property 

 is quite specific, so that this antibody may appropriately 



