Inheritance Materials of Germ-Cells 87 



that all other male substances tlian chromatin arc excluded 

 as rigidly as would be required by experiments in a chemical 

 hiboratory designed to ascertain tlie action of a particular 

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

 for example, that in almost if not (juite all male genninal 

 elements in animals, a thin outer layer from the cytoplasmic 

 part of the spennatid 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 Qgg at 

 fertilization. Nor is there any good ground for su})posing 

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

 solutely excluded. The almost certain presence in the cg^g 

 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 (^gg. 

 Their action would be conceived to involve the entire ovum 

 ah 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 far as its main aim is conccrnrd. We are 

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

 or how completely it changes its nomenclatural habiliments, 



