LUTHER BURBANK 



mystifying and thought-compelling of biological 

 revelations. 



If any one were to doubt that the intimate 

 chemical structure of plant protoplasm and plant 

 juices may thus be depended on to reveal genetic 

 relationships, and to mark nice shades of distinc- 

 tion between allied forms, evidence from a quite 

 alien field might be cited that would set the matter 

 at rest. 



EVIDENCE FROM THE ANIMAL WORLD 



The evidence in question is furnished by an 

 extraordinary series of blood tests through which 

 Dr. G. H. F. Nuttall, the American Professor of 

 Biology at Cambridge University, has traced the 

 intimate relationship of large numbers of animals 

 of different orders. 



By inoculating rabbits with the blood of dif- 

 ferent species of birds, reptiles, and mammals, 

 Dr. Nuttall was able to develop an extraordinary 

 serum with which the intimate constitution of the 

 blood of other species of animals could be tested. 

 He thus demonstrated, for example, that lizards 

 and serpents are more closely related than turtles 

 and crocodiles, but that all these reptiles are 

 nearer to one another than they are to birds, and 

 nearer to birds than to mammals. 



He showed that the dog carries in every drop 

 of its blood chemical proof of closer relationship 



[48] 



