REPRODUCTION 71 



It is evident from these brief statements 

 that the two parents supply very unequal 

 amounts of material to the offspring. The 

 father contributes merely one spermatozoon 

 whose volume is surely not over 50 cubic micra 

 or thousandths of a millimeter; the mother 

 contributes the substance of the egg cell, 

 which, if it be regarded as spherical and with 

 a diameter of 150 micra, would have a volume 

 of 1,767,150 cubic micra, or over 35,000 times 

 that of the sperm cell. Not only is this true, 

 but the mother likewise contributes from the 

 substance of her body all the nourishment that 

 enables the diminutive egg to grow to a fully 

 formed babe. Hence the material of the child's 

 body is vastly more maternal than paternal in 

 its origin. 



Notwithstanding the disparity between the 

 amounts of material contributed by the two 

 parents to the offspring, it is well established 

 that in any population as a whole the children 

 show about as much resemblance to the father 

 as to the mother ; in other words, in inheri- 

 tance the mother has no more influence than 

 the father. This condition has led to a closer 

 scrutiny of the actual contributions of the two 

 parents. 



