The figures on these two cuts represent the development of a 

 uni-cellular arche-type and of a multi-cellular animal which pre- 

 served the simple form of a skin-and-stomach type. This is the 

 idea of Haeckel as to the development of the simplest forms of 

 animal life. To the right, we see the way in which a coral- 

 animal, Monoxenia Darurinii, develops from the egg-cell. This 

 cell divides into two cells, then into four, and finally, into a 

 lump of cells. This lump develops fine bristles on its exterior 

 surface, by means of which it revolves through the water. At 

 the same time it forms a hollow in its center, then doubles up 

 tgainst itself, until it becomes a double-walled (skin-and-stomach) 



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