180 ARTIFICIAL PARTHENOGENESIS AND FERTILIZATION 



this is actually the case. Thus unfertilized eggs were distributed 

 among the following solutions : 



(1) 25 c.c. m/2 NaCl+0. 1 c.c. m/10 sodium oleate 



(2) 25 c.c. m/2 NaCl-j-0.1 c.c. m/10 sodium oleate-f 0.2 c.c. N/10 



NaOH 



(3) 25 c.c. m/2 NaCl+0.2 c.c. N/10 NaOH. 



In the first solution, the eggs became angular, but hardly 

 one formed a membrane; in the second solution, 50 per cent of 

 the eggs formed very delicate membranes that soon tore, and 

 many of the eggs cytolyzed ; in the third case the eggs remained 

 quite intact. 



But cytolysis of the eggs in the soap solution can also be 

 obtained by raising the concentration of the soap solution high 

 enough. Thus, if the eggs are put into 50 c.c. m/2 NaCl+1 c.c. 

 m/10 sodium oleate, membrane formation and cytolysis begin 

 practically at once. I suppose such a solution has a faintly 

 alkaline reaction. If excess of HC1 is added to this mixture, 

 membrane formation is not prevented; in this case free oleic 

 acid is formed, and this, as I observed in 1905, also initiates 

 membrane formation and cytolysis in the egg. 



We have already seen that an alkaline solution of NaCl 

 without soap has only a relatively weak cytolytic effect. The 

 addition of 0.2 c.c. of m/10 sodium oleate+0.4 c.c. N/10 

 NaOH to 50 c.c. of NaCl has just as much effect as the addi- 

 tion of 2 c.c. NaOH without soap. 



Now it is easj' to convince oneself of the effect of soap in 

 causing development. It is only necessary to transfer the eggs 

 after a short time from the soap solution to ordinary sea-water, 

 and subsequently (after repeated washing) expose them to 

 hypertonic sea-water. The following example will illustrate 

 this: Unfertilized eggs were placed in 50 c.c. m/2 NaCl-f- 

 0.2 c.c. of sodium oleate and after two or three minutes trans- 

 ferred to sea-water. The majority of the eggs formed mem- 

 branes and only a few cytolyzed. The eggs were washed 



