WHAT IS THE OFFICE OF THE SPERM-CELL ? 337 



one which implies an essential and indispensable differ- 

 ence in the two processes, and in the two results. But 

 if the Hydra produced from a bud is in every respect 

 the same as the Hydra produced from an ovum, and is 

 capable in its tiu-n of producing buds and ova, we can 

 hardly suppose this identity of result to arise from 

 processes essentially dissimilar. If the Bee, or Moth, 

 produced from an unfertilised egg is precisely similar 

 to the Bee or Moth produced from the fertilised egg, 

 and is capable of producing offspring in the same way, 

 we can hardly suppose this identity of result to arise 

 from i^rocesses essentially dissimilar. We may distin- 

 guish the process of the union of two cells from that 

 of the simple division of one cell, and call this union 

 by the name of Generation ; and there will be obvious 

 convenience in having such a name ; but if the result 

 of Generation is the production of an animal perfect in 

 all its parts, and capable of propagating its species, it 

 is quite clear that the union of two dissimilar cells is 

 not the essential and fundamental process necessary for 

 such a result, since the result is frequently attained 

 without it. When we consider Generation in the 

 higher animals, we seem justified in establishing the 

 union of germ-cell and sperm-cell as the distinctive and 

 indispensable condition ; but when we consider Genera- 

 tion in the abstract, and observe its phenomena in the 

 simpler animals, we are forced to admit that this condi- 

 tion is no longer distinctive and indispensable, but that 

 the union of the two cells is a secondary and derivative 

 ' process, not the fundamental process of Generation. 



Y 



