GROWTH AND GENERATION. 331 



able causes, they are still smaller, they grow into 

 branches ; and thus we see that, according to circum- 

 stances, different organs are capable of being elimin- 

 ated from the same structure." * In conclusion, let 

 us remember that the eg^ itself is an out-gTOwth, not 

 a starting-point ; as all know who have made them- 

 selves acquainted with the results of embryological 

 research, in which the phases of the genesis of the egg- 

 are minutely recorded ; this genesis being the same 

 essential process observed in all other forms of Growth. 



Let us now examine the old position, which declares 

 that the union of two different elements, a germ-cell 

 and a sperm-cell, is the act of Generation — an act sui 

 generis, and altogether distinct from the act of cell- 

 multiplication, or Growth, which is regarded simply 

 "as a modification of the nutritive function." The 

 act of union, hitherto regarded as the fundamental act 

 of all Eeproduction, is only, I believe, a subsidiary, 

 derivative process, and not by any means the " ultimate 

 fact" at which our researches must pause ; a conclu- 

 sion to which Goethe pointed when he showed that 

 Growth and Eeproduction in plants are but different 

 aspects of the same law. 



Let us consider the known facts of Eeproduction 

 in their ascending order of complexity. What is the 

 simplest process known ? It is that of a cell spon- 

 taneously multiplying itself by subdivision. In the 

 albuminous and starchy fluid, named jprotoplasma, a 

 single cell appears. It assimilates more and more of 



* Penzance Nat. Hist. Society Rej^ortfor 1S50, p. 374. 



