202 The Mechanistic Conception of Life 



phenomena of artificial parthenogenesis are linked together with 

 the phenomena of hemolysis which at present play so important 

 a role in the study of immunity. The difference between 

 cytolysis (or hemolysis) and fertilization seems to be this, that 

 the latter is caused by a superficial cytolysis of the egg, while if 

 the cytol>i:ic agencies have time to act on the whole egg the 

 latter is completely destroyed. If we put unfertilized eggs of a 

 sea-urchin into sea-water which contains a trace of saponin we 

 notice that, after a few minutes, all the eggs form the typical 

 membrane of fertilization. If the eggs are then taken out of the 

 saponin solution, freed from all traces of saponin by repeated 

 washing in normal sea-water, and transferred to the hypertonic 

 sea-Avater for from thirty-five to fifty-five minutes, they develop 

 into larvae. If, however, they are left in the sea-water con- 

 taining the saponin they undergo, a few minutes after membrane 

 formation, the disintegration knoTvn in pathology as cytolysis. 

 Membrane formation is, therefore, caused by a superficial or 

 incomplete cytolysis. It is possible that the subsequent treat- 

 ment of the egg with hypertonic sea-water is partly needed to 

 overcome the destructive effects of this cytolysis of the cortical 

 layer. 



Many pathologists assume that hemolysis or cytolysis is 

 due to a liquefaction of certain fatty or fat-hke compounds, 

 the so-called lipoids, in the cell. If this view is correct, it 

 would be necessary to ascribe the fertilization of the egg to the 

 same process. 



The analogy between hemolysis and fertilization throws, 

 possibly, some light on a curious observation. It is well knoAATi 

 that the blood corpuscles, as a rule, undergo cytolysis if injected 

 into the blood of an animal which belongs to a different family. 

 The writer found last year that the blood of mammals, e.g., the 

 rabbit, pig, and cattle, causes the egg of Strongylocentrotus to 

 form a typical fertilization membrane. If such eggs are after- 

 ward treated for a short period with hj^Dertonic sea-water they 



