122 



THE EVOLUTION OF MAN. 



present position of the cell theoiy, and as to the views 

 commonly held in connection with it. 



Fig. 1. — The human egg from the ovary of the female; much enlarged] 

 The entire egg is a simple, globular cell. The greater part of the spherical 1 

 egg-cell is formed by the egg-yelk, or the granular cell-substance (proto- 

 plasm), which is composed of innumerable, delicate yelk-grannles, with aj 

 little intervening substance. The germ-vesicle, answering to the eell-| 

 kernel (nucleus) lies in the upper part of the yelk. It contains a dark! 

 nucleolus or germ-spot. The globular mass of yelk is surrounded by 

 thick transparent egg-membrane (zona peUucida, or chorion). This isl 

 penetrated by the pore. canals, in the form of very numerous hair-like lines,! 

 which run radially towards the centre of the globe ; through these the! 

 thread-shaped, moving sperm-cells pass, in the process of impregnation, intol 

 the egg-yelk. 



In order rightly to appreciate the Cell Theory, whichj 



