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THE AMERICAN NATURALIST [Vol.XLV 



activity of other cellular constituents, there is no war- 

 rant for jumping to the conclusion that they are essen- 

 tially more important than these other constituents. I 

 may repeat in this connection what I have had occasion 

 to say by way of reminder in a former paper, "A germ- 

 cell in fact should need no special units to generate the 

 peculiar genre equilibrium or idiosyncrasy of protoplasm 

 which is distinctive of a particular kind of individual, 

 since such a germ-cell not only is itself already an indi- 

 vidual, but from the very fact of having had the same 

 racial history as other individuals of its peculiar kind 

 (be they germ-cell, embryo or adult) it must likewise as 

 a whole already possess this distinctive idiosyncrasy." 

 That is, the individual proteids of germ-cells— globulins, 

 albumins, nucleoproteids and the like — bear from the 

 very start the stamp of individual peculiarity, wherever 

 they may reside in the cell. And since they constitute at 

 least part of the materials which transform and inter- 

 act and have their actions modified by enzymes, certainly 

 they as much as the enzymes are responsible for the out- 

 Regarding the specificity of corresponding proteins 

 in relation to the natural kinships of living organisms, 

 some very interesting facts are brought to light in the 

 recent voluminous and painstaking researches of 

 Reichert and Brown. 12 They show, for instance, that in 

 haemoglobin, one of the few crystallizable .proteins, the 

 crystals of each species of any genus, while possessing a 

 constant individuality, all belong to the same crystallo- 

 graphic system and generally to the same crystallo- 

 graphy group of the system. These authors further 

 point out the fact that this isomorphism must signify in 

 all probability correspondence in the fundamental chem- 

 ical constitution and molecular configuration of respect- 

 ive haemoglobins. In case of the individual species the 

 difference in the characters of the crystals was found to 

 be as great as with ordinary chemical salts or minerals 

 that belong to an isomorphous group. One is seemingly 



"Univ. t i c UStudie Bet ten \ er Oct ber p] 1 19 1909. 



