The Organism and its Protoplasm 147 



twecii different kinds as follows: "The general statement 

 may be made for both cases [grafting and fertilization] that 

 closely related species combine more readily than those far 

 a])art, i.e., the results are more successful for unions be- 

 tween closely 'related' forms than between distantly 'related' 

 forms. Certain exceptions exist, however, in both direc- 

 tions." ^^ 



But while the fusibility or non-fusibility of the tissues of 

 diff'erent animals as revealed by Wilson's methods are phe- 

 nomena closely related to the compatibility or non-compati- 

 bility of scion and stock in plant grafting, the former would 

 seem to be, so far as the methods can be emploj^ed, a con- 

 siderably better test of the specificity of the protoplasms 

 of different individuals and species. This is so because by 

 comminuting the animals, as Wilson does, and then thor- 

 oughly mixing the elements, every part and kind of substance 

 of the one may be supposed to be brought into contact with 

 every part and kind of substance of the other, whereas in 

 grafting only a relatively small portion of the scion can 

 actually touch the stock, and generally speaking only in 

 such manner that the corresponding kinds of substance i.e., 

 corresponding tissues, come together. From this it may well 

 be, that there is really more specificity of substances in the 

 ordinary graft than might at first thought be inferred from 

 the perfection of the union. Actual fusion may occur only 

 between some substances of each party to the union, and 

 the general life and activities of the graft may be kept up 

 through its ordinary metabolic processes, it, however, using 

 as food to some extent, substances received from its host, 

 instead of wholly from the outside world. 



Indeed some such interpretation as this appears to be 

 necessitated by the strict maintenance of type of both 

 graft and host. From this standpoint a successfully grafted 

 individual plant or animal might be defined as a partnership 

 in which each partner while maintaining most of its own 



