Inheritance Materials of Germ-Cells 87 



that all other male substances than chromatin are excluded 

 as rigidly as would be required by experiments in a chemical 

 laboratory designed to ascertain the action of a particular 

 chemical element or substance in its purity. It is certain, 

 for example, that in almost if not quite all male germinal 

 elements in animals, a thin outer layer from the cytoplasmic 

 part of the spermatid is present on the head of the sperma- 

 tozoon. Furthermore, it is well known that at least the 

 "intermediate piece" of the sperm tail, which is not usually 

 regarded as chromosomal in origin, remains in the egg at 

 fertilization. Nor is there any good ground for supposing 

 that the non-chromatinic portions of the nucleus are ab- 

 solutely excluded. The almost certain presence in the egg 

 at fertilization of at least these male substances other than 

 chromatin can by no means be regarded as insignificant for 

 heredity, especially if the initiator conception of germinal 

 material is held. It seems to follow of necessity that if the 

 fertilizing substances, whatever their source, be conceived 

 to act in an organic system of the physical chemistry sort 

 after the manner of enzymes, no such quantitative relation 

 subsists between these fertilizing substances and the prod- 

 ucts of organic growth as the chromosome theory implies ; 

 nor can their action be so narrowly localized in the egg. 

 Their action would be conceived to involve the entire ovum 

 ab initio, and not the chromosomes alone. 



Summing Up of the Findings Against the Chromosome 



Theory 



The general result of our critique is that the whole at- 

 tempt to interpret the physical basis of heredity in accord- 

 ance with elementalist conceptions has failed and must con- 

 tinue to fail, so fat as its main aim is concerned. We are 

 led to see that the germ-plasm dogma, no matter how often 

 or how completely it changes its nomenclatural habiliments, 



