Cell-Theory not Sufficient -for Explaining Organism 185 



that if Holmes uses "cells" in the ordinary sense, his specula- 

 tion is distinctly a backward step from the conceptions 

 presented by Roux in his Struggle of the Parts, who, so 

 far as the constitution of the organism is concerned, frankly 

 recognizes several orders of parts, and concerns himself very 

 little or not at all with vital units. For instance, he dis- 

 cusses the struggle of the Molecules, of the Cells, of the 

 Tissues, and of the Organs. 



It seems worth while to call attention to this because 

 while professedly adopting Roux's conceptions to a con- 

 siderable extent. Holmes believes he has improved upon his 

 forerunner in staking less than the latter does on the 

 eliminative aspect of the struggle theory. In this I agree 

 with Holmes, but must at the same time maintain, as above 

 indicated, that in attempting to conceive the struggle in 

 the terms of cells, regarding these as vital units in an ulti- 

 mate sense, he falls considerably behind Roux in speculative 

 soundness and very far behind him in *the methodological 

 usefulness of his speculation. 



The objection to the aggregative conception of the organ- 

 ism, no matter under what form it presents itself, is so 

 conclusive that little time need be taken in presenting it: 

 There is not an atom of etidence that is really in its favor. 

 Even the facts which at first sight seem most favorable 

 to it, namely those of symbiosis on which Holmes chiefly 

 relies, are found when considered a little more closely, to 

 oppose it. No symbiotic combination known, even that be- 

 tween the alga and the fungus to make the lichen, ever 

 occurs as one organism in the sense that any true organism 

 is one. The symbiotic, or partnership organism, if organism 

 it can justly be called at all, never begins its individual life 

 as a single reproductive cell, either as a spore or as a zygote, 

 i. e., a fertilized ovum, but each species has to reproduce 

 itself, just as though the association did not occur. As a 

 matter of fact, in nearl}'^ all known cases of symbiosis one 



