Fig. 14. — A, hybrid larva of Sphcprechinus ? , and Echinus 5 ; front 

 view. B, tlie same ; oblique, side view. C, dwarf hybrid larva of 

 Spharechinus $ (non-nucleated egg fragment), and Echinus 3 , of 

 pure Echinus type. D, the same larva in side view. (After 

 Boveri.) 



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