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,! 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 Abnandlungen, Berlin, 1896, p. 148. 
