248 BKEEDING 



body from the centre of the Graafian vesicle to its circumference. Tlie 

 germinal vesicle itself, as maturity in the ovum advances, becomes rela- 

 tively smaller, owing to the more rapid growth of the structures with which 

 it is associated. 



AVhile the ovum is advancino- to the circumference of the Graafian 

 vesicle, the granular contents of that vesicle are pushed to the inner side 

 of the investing membrane which forms its wall, and become the membrana 

 granulosa, in which the ovum itself is embedded. 



According to modern views, the germinal vesicle, during the growth 

 of the structures of the ovum, undergoes changes which result in its 

 temporary obliteration, and the substitution of a spindle-shaped body at 

 each end of which the elements of the yolk are clustered. 



All the developmental actions which have been referred to as occurring 

 in a single ovum, it will be understood, are going on at the same time in 

 a number of ova enclosed in the ovaries. In fact, it is not unreasonable to 

 presume that, from early life, ova are constantly being developed and dis- 

 charged as effete matter, falling short of the indefinable something wliich 

 would give them the right to take rank among the actual, or, at the least, 

 possible, entities. 



To continue the story, it must be granted that one or more of several 

 mature ova meet the sperm-cells, which can start their dormant life into 

 activity, and in such case on the instant of contact commence the changes 

 which end in the formation of a miniature representation of tlie parent. 



CHANGES IN THE OVUM AFTER IMPREGNATION 



At what stage of its progress from the ovarium through the Fallopian 

 tubes to the cavitv of the uterus the ovum meets the sj^erm-cell from the 

 seminal fluid is not known. Most probably the point of contact is purely 

 accidental. The spermatozoa are capable of rapid movements, and may 

 meet the advancing ovum at any point of its course, even from the moment 

 of its exit from the Graafian cell. Wherever the contact between the germ- 

 cell and the sperm-cell occurs, the resulting changes are Avonderful and also 

 inexplicable. 



First it is evident that active developmental powers exert themselves, 

 and effect in the contents of the ovum remarkable structural changes. 

 Next it may be predicated that the male sjjermatic fluid imparts certain 

 qualities and characters to the germ, such as form, constitution, and dis- 

 position, which belong to the male, as it later becomes evident that the 

 female parent also shares the power of transmitting these cjualities in vary- 

 ing proportion. 



