No. 637] 



IMMUNE SERA 



115 



traction. Shall we conclude that such a lar rcu-liiii- in- 

 fluence as this, particularly in a developin*i-(iro;;inisiii, will 

 pass the germ-cells by unscathed? 



Similarly, growth in man is known to be controlled by 

 a pituitary secretion that is carried by the blood to the 

 various organs. The normal development of secondary 

 sexual characters is determined by products from the 

 testes or ovaries, and the activities of the generative 

 organs themselves are intimately associated with the 

 functioning of the adrenal and other glands. The periods 

 of ovulation are inhibited by secretions from the corpus 

 luteum; lactation is incited by products of the corpus 

 luteum, the involuting uterus and the placenta ; the car- 

 bohydrate metabolism in the liver and even in the most 

 distant muscles is profoundly influenced by substances 

 formed in the pancreas; the pancreas, liver, and intes- 

 tinal glands are set to secreting through the stimulus of 

 a product formed in the duodenal and jejunal mucosa?. 

 And still others of such remarkable interrelations can be 

 cited. 



Truly one may pronounce that social complex of recip- 

 rocating individuals termed cells which make up an 

 organism, "members one of another." And with all 

 of these cooperative activities of the various parts of the 

 body it is inconceivable, to me, at least, that the germ- 

 cells, bathed in the same fluid, nourished with the same 

 food, stand w^holly apart. 



May we not surmise then that as regards inheritance 

 and evolution, Lamarck was not wholly in error when he 

 stressed the importance of use and disuse of a part, or 

 of modifications due to environmental change, in altering 

 the course of the hereditary stream, particularly if we 

 conceive of these influences as being prolonged, possibly 

 over many generations? Have we not in the serological 

 mechanism of the body of animals an adequate moans for 

 the incitement of the ovmiiiial clianuvs which ihkI.tIv 

 certain aspects of evolution.' 



