THE BIOLOGY OF THE CELL SURFACE 



of two or more^ which were only fortuitously combined in 

 the spermatozoon" (Italics are mine). According to him 

 it is a fact which he has proved that "the membrane forma- 

 tion by the spermatozoon is caused also by a cytolytic 

 agent- — a lysin." 



I have already pointed out that for the sea-urchin's egg 

 Loeb used butyric acid either too long or in too great con- 

 centration; such over-exposures very greatly increase 

 the rate at which this e^^ cytolyzes in sea-water.^ The 

 optimum exposure to butyric acid, which for the egg of 

 Arbacia Loeb never knew, does not cause this hastening of 

 cytolysis. Moreover, neither Loeb nor any one else has 

 proved the presence of a lysin or of a "fortuitously com- 

 bined combination" of chemical agents in the spermato- 

 zoon. Loeb's so-called proof of a lysin in the spermatozoon 

 is fantastic and wholly specious. 



Li calling forth membrane-separation the effect of butyric 

 acid is, to be sure, somewhat similar to that of the sperma- 

 tozoon. But there is never membrane-separation in the 

 butyric acid solution; only after the acid is washed away 

 by bringing the eggs into a large volume of sea-water does 

 membrane-separation take place. There is thus an essen- 

 tial difference between the immediate action of the sperma- 

 tozoon in calling forth membrane-separation and the 

 delayed effect of butyric acid. This point raises a further 

 question. Since according to the author of the superficial 

 cytolysis-corrective factor theory of fertilization, butyric 

 acid is only an example of a large class of cytolytic (and 

 haemolytic) agents, we must ask if the action of butyric 

 acid is, as we should expect and as the author of the theory 

 claims, characteristic of the class. 



^ The "'or more'' I think is added as a margin of safety since the 

 theory demands only two. 

 - Just, I()20. 



232 



