170 DYNAMICS OF LIVING MATTER 



the acid effect is essential in these experiments, that not all the acids 

 can be used in these experiments. HNO 3 , HC1, H 2 SO 4 and dibasic 

 or tribasic organic acids such as oxalic or citric, etc., could not 

 be used, while CO 2 called forth the membrane formation. 



The order in which the two agencies are employed is not a matter 

 of indifference. When the eggs are first exposed to the above-mentioned 

 hypertonic sea water for about twenty to fifty minutes and then sub- 

 mitted to a process which calls forth the membrane formation (e.g. to 

 the treatment with fatty acid), the eggs form a membrane, but will 

 not develop into larvae. As a rule, they disintegrate within twenty-four 

 hours, and behave in every way as if they had been treated with the acid 

 alone. If one wishes to treat them with hypertonic sea water first, they 

 must remain in this solution for about from one and one half to two 

 hours. If after this time the membrane formation is called forth, 

 almost all the eggs develop, and a number of the larvae rise to the sur- 

 face. This method also gives good results. 



If in eggs the membrane formation is called forth first, and if they 

 are subsequently exposed to the above-mentioned hypertonic sea water 

 for more than fifty minutes, either no egg develops or the development 

 is very abnormal. 



All the facts mentioned in this and the previous communications 

 indicate that the process of membrane formation is an essential and 

 not a secondary phenomenon in this method of artificial partheno- 

 genesis. 



Five years ago I ventured the suggestion that the process of 

 membrane formation is a process of coagulation. It is, however, 

 obvious that the membrane formation in these experiments cannot 

 be attributed to an acid coagulation, as in this case the membrane 

 formation should occur while the eggs are in the acid, and not after 

 they are taken out. Moreover, the fact that only certain acids act 

 in this way also excludes such an opinion. These facts suggested the 

 possibility that the fatty acids did not produce the membrane forma- 

 tion through the H-ion, but by the anion or the undissociated molecule, 

 and that, moreover, the H-ion directly antagonized the membrane 

 formation. This idea was tested and found correct. If a fatty acid is 

 added to benzol sea water, the eggs are no longer able to form a mem- 

 brane while they are in this mixture, though they form a membrane 

 while they are in benzol sea water which is free from fatty acid. From 

 a closer observation of the process of membrane formation I am in- 

 clined to believe that it is due to a process of secretion, i.e. the squeez- 

 ing out under pressure of a liquid from the interior of the egg.* I am 



* Loeb, PflugeSs Archiv, Vol. 103, p. 257, 1904. 



