THE WONDERS OF LIFE 



substances; and, in fact, are true in a higher degree of 

 these, as the metabolism of the living matter causes a 

 constant displacement of the atoms. This is caused, 

 according to the view of Franz Hofmeister and others, 

 by the formation of ferments or enzyma — in other 

 words, by catalysators of a colloidal structure. Verworn 

 has, on physiological grounds, given the name of biogens 

 to these plasma-molecules. 



The profound insight which comparative anatomy has 

 given us into the significance and nature of organs, and 

 comparative histology into those of the cells, has nat- 

 urally excited a desire to penetrate in the same way the 

 mystery of the elementary structure of the plasm, the 

 chief active constituent of the cell. The improved meth- 

 ods of modern cytology, and the great progress which 

 this science of the cell owes to the microtome and to 

 microchemistry with its delicate coloring processes, etc., 

 have prompted many observers of the last three decades 

 to study the finest structural features of the elementary 

 organism, and on this foundation build hypotheses as to 

 the elementary structure of protoplasm. In my opinion, 

 all these theoretical ideas, in so far as they would explain 

 the finer structure of pure plasm, have a very serious 

 defect; they relate to microscopic structures which do 

 not belong to the plasm as such (as a chemical body), 

 but to the cell -body (or cytosoma), the chief active 

 constituent of which is certainly the plasm. These 

 microscopic structures are not the efficient causes of the 

 life-process, but products of it. They are phylogenetic 

 outcomes of the manifold differentiations which the 

 originally homogeneous and structureless plasm has 

 undergone in the course of many millions of years. 

 Hence I regard all these "plasma-structures" (the 

 comb, threads, granules, etc.), not as original and 

 primary, but as acquired and secondary. In so far as 

 these structures affect the plasm as such, it must take 



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