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THE AMERICAN NATURALIST [Vol.LVI 



is of much interest from the standpoint of our quest of a 

 possible connection between reaction-products of the body 

 and alterations of the germ is the fact that he feels con- 

 strained to link up his serumal phenomena with the chro- 

 mosomes. Thus, he says, The chemical individuality- 

 character of the chromosomes should lead to analogous 

 chemical differences consisting perhaps in the formation 

 of chemical side-chains attached to proteins ; they should 

 be present primarily in cell-proteins and secondarily in 

 the proteins of the body-fluids. . . . These side-chains 

 must be identical in all the proteins of the same indi- 

 vidual and differ in the case of different individuals." 



Another great group of influences which extend to the 

 furthermost reaches of the body and profoundly affect 

 the entire organism in development and in maturity— 

 those emanating from the various endocrine structures — 

 I have barely time to mention. They must be kept in 

 mind, however, when we attempt to picture the ebb and 

 flow of chemical influence which is indispensable to the 

 maintenance of general physiological equilibrium, inclu- 

 ding that of the gonads no less than of the other body 

 stnictiiro>. 



^'(.u may i'rvl that in reviewing the nature of the protein 

 iiK.l.MMile, tlie behavior of the proteins of the cells in 

 morpliogenesis, the gradational specificities of the im- 

 munological reactions, the relationships wliit-h cxi-t be- 

 tween host and transplant, and in reminding \ nu ot' tlie 

 intricate functions of the endocrines, I have waiidcicd 

 far afield into irrelevant byways, but I hasten to assert 

 that these phenomena are not as unrelated as might ap- 

 pear at first sight ; they are but different aspects of the 

 great salient fact of organismic unity, whether it be a 

 matter of chemical constitution, taxonomic relationship 

 or physiologic response. 



And now I wish to raise the question of whether or 

 not ill the light of the foregoing facts it is irrational to 

 iMli.xr that in all probability a thread of chemical iden- 

 t!t\ p('i>i>ts between the chemical constituents of the 

 germ and the chemical substratum of the ti,^sii(>-.'(^ll<. 

 The nuclei of the various tissue-cells dil'tVr litth' In ap- 

 pearance from the nuclei of the germ-cells, and inasmiich 

 as the new germinal and somatic cells descend alike 



