BEARERS OF THE HEREDITARY QUALITIES 63 



from the foregoing and other arguments may be illustrated by 

 two or three quotations from recognised authorities. Prof. O. 

 Hertwig says : " The female nuclear material transmits the 

 characters of the mother, the male nucleus those of the father, 

 to the offspring." Prof. Strasburger says for higher plants : 

 " The process of fertilisation depends upon the union of the 

 sperm-nucleus with the nucleus of the egg-cell ; the cell- substance 

 (cytoplasm) does not share in the process; the cell-substance 

 of the pollen -grain is only the vehicle to conduct the generative 

 nucleus to its destination." Prof. Weismann says : " We can 

 hardly ascribe to the body of the ovum a higher import than 



FIG. 16. A pollen grain, a, the two nuclei, with their chromosomes; 

 b, the general protoplasm ; c, the outer wall. (From Carnoy.) 



that of being the common nutritive basis for the two conjugating 

 nuclei." 



Criticism. i. "The life of a complex multicellular organism 

 certainly depends upon the inter-relations and interactions of 

 many parts ; the life of a cell apparently depends upon the 

 inter-relations and interactions of different parts of the cellular 

 organisation, especially on the give-and-take between nucleo- 

 plasm and cytoplasm ; and it is not unlikely that life itself 

 i.e. vital activity or function may depend upon the inter- 

 relations and inter-actions of a number of complex substances, 

 none of which could by itself be called alive. Just as the secret 



