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THE HISTORY OF CREATION. 



egg,- this process of development always begins by the 

 simple egg-cell (Fig. 3) forming an accumulation of cells 



Fig. 4. — First commencement of the development of a mammal's egg, tlie 

 ao-called " cleavage of the egg " (propagation of the egg.cell by repeated 

 self -division) . A. The egg, by the formation of the first furrow, falls into 

 two cells. B. These separate by division into four cells. C. The latter 

 have divided into eight cells. D. By repeated division a globular accumu- 

 lation of numerous cells has arisen. 



(Fig. 4) by continued self-division. The outer covering, or 

 cell membrane, of the globular egg remains undivided. First, 

 the cell-kernel of the egg (the so-called germinal vesicle) 

 divides itself into two kernels, then follows the cell-sub- 

 stance (the yolk of the egg) (Fig. 4 J.). In like manner, 

 the two cells, by continued self-division, separate into four 

 (Fig. 4 B), these into eight (Fig. 4 (7), into sixteen, thirty- 

 two, etc., and finally there is produced a globular mass of 

 very numerous little cells (Fig. 4 D). These now, by further 

 increase and heterogeneous development (division of labour), 

 gradually build up the compound many-celled organism. 

 Every one of us, at the commencement of our individual 

 development, has undergone the very same process as that 

 represented in Fig. 4. The egg of a mammal — represented in 

 Fig. 3, and its development in Fig. 4 — might as well be that 

 of a man, as of an ape, dog, horse, or any other placental 

 mammal. 



