78 The Unitij of the Organism 



The second and more fundamental qualifying considera- 

 tion is that, knowing as he does something of the methods 

 by which the chemist gets at the chemical substances of or- 

 ganisms in order to describe them, the naturalist is unable 

 to suppose the compounds and processes described by his 

 chemical coworkers to be anything better than more or less 

 distant approaches to the substances that actually exist, 

 and the processes that actually go on in the organism as the 

 naturalist is primarily concerned with it ; that is, as living 

 normally. The naturalist accepts not only without hesita- 

 tion but with eagerness and gratitude the chemist's report 

 on what he is able to get out of the organism. That these 

 reports come near setting forth what the organism actually 

 is, the naturalist is bound to recognize cannot be the case. 



This reservation the naturalist feels the more justified in 

 making by noticing that there are physiologists of unques- 

 tioned standing who hold views which amount really to the 

 same thing. Thus the distinction between living and dead 

 albumen (Eiweiss), first sharply drawn by Pfliiger (Ueber 

 die physiologische Verbrennung in den lebendigen Organis- 

 men, Archiv fiir die gesamten Physiologic, Bd. 10, 1875) 

 and since recognized by other investigators hardly less 

 eminent is manifestly of the same import. ( See, for example, 

 j\Iax Verworn, p. 596, Allegemeine Physiologic, sechstc Aufl.) 



The Organism as a Chemical Laboratory 



Immediately the fertilized Qg^r begins to develop, chemical 

 substances are produced within it. Among the higher ani- 

 mals the hen's ^gg has been the most studied in this as in 

 many other aspects. "Neither nucleo-proteins nor pentoses 

 are present in the fresh (^gg-, and purine bases are present 

 only in very small amounts. The fact that during develop- 

 ment these substances rapidly increase in amount indicates 

 therefore that a synthesis of nucleo-protein from the reserve 



