42 ARTIFICIAL PARTHENOGENESIS AND FERTILIZATION 



predominate. One can understand that for the utilization of 

 such solid fats in the egg, a process must come into play, which 

 is superfluous in seeds that contain oil, on account of the 

 original fluid state of the oil: that process is the liquefaction 

 of the fat. We have already mentioned that this circumstance 

 can be taken into consideration in the membrane formation of 

 eggs. It may, in a word, depend upon the fact that at mem- 

 brane formation the fats or lipoids are converted into a form 

 in which they can be more easily decomposed or oxidized. 



A clearer analogy between the germination of the seed and 

 the development of the egg is the fact, already proved by 

 Moritz Traube, 1 that the germination of the seed too is only 

 possible in the presence of free oxygen. In the beginning of 

 germination in the seed, just as in the beginning of develop- 

 ment in the egg, we are dealing with a causation of syntheses 

 out of the constituent parts of the cytoplasm, and for this 

 process free oxygen is necessary; and moreover, nuclear and 

 cell division are also concerned, for which, likewise, free oxygen 

 is necessary. 



1 Moritz Traube, Gesammelte Abhandlungen, Berlin, 1896, p. 148. 



