The Unity of the Organism 



most careful investigation, that the protoplasm and the 

 sarcode of the lowest organisms are identical" l "However, 

 Max Schultze in particular . . . produced incontrovertible 

 evidence that the protoplasm of plants and animals and the 

 sarcode of the lowest organisms are identical stuffs." "As 

 the culmination of a long period of work, Max Schultze, in 

 1861, placed the conception of the identity between animal 

 sarcode and vegetable protoplasm upon an unassailable 

 basis, and therefore he hW received the title of 'the father 

 of biology.' " l "Protoplasm, the physical basis of life, 

 the living part of every living being, and essentially the 

 same in its general properties and functions in all. . . ." 



These quotations, picked up at random, will perhaps suf- 

 fice to illustrate the wide prevalence of the view. But though 

 widely held, acquiescence to it is by no means universal and 

 whole-hearted, judging from a considerable number of ex- 

 pressions that might be cited. 



This not being the place to present in detail the facts and 

 arguments which make the conception of the absolute iden- 

 tity of all protoplasm untenable, I shall do no more than 

 put this question to those biologists who subscribe to the 

 creed : In the light of what we now know about the reactions 

 of the blood of animals of different genera and even species 

 to one another, and about the chemical composition of the 

 nitrogen-containing substances of tissues and elements in 

 different groups of organisms, if the protoplasm of a dog, 

 say, could be wholly removed, and that of a fish or even a 

 tree could be substituted, would the dog continue to be the 

 same dog, and none the worse for the change? No biologist 

 untrammeled by speculative considerations will hesitate to 

 answer this negatively, unless, indeed, it seems too ridiculous 

 a question to deserve serious treatment. Yet if the "con- 

 ception of the identity between animal sarcode and vegetable 

 protoplasm" is warranted by what nature actually presents 

 to us, the answer would certainly have to be diametrically 



