404 OTTO GLASER. 



retardation I supposed to be due to the depression in the rate of 

 oxidation. This assumption, as I pointed out, does not seem 

 unreasonable; on the other hand as I pointed out more recently, 

 retardation of development may in this case also be due to inter- 

 ference with, or depression of, other processes no less essential. 

 Only further work can decide these questions. 



2. The Fertilizin Theory. In the fertilizin theory, no particular 

 role is assigned to the increased permeability. 'The nature of 

 the effect of the activated fertilizin on the egg is analogous in 

 some respects to a superficial cytolysis, in this respect agreeing 

 with Loeb's theory. But the 'lysin' 1 is contained in the egg, 

 not in the sperm as Loeb thought; if cytolysis is involved, it is 

 a case of auto-cytolysis. This may involve increase of permea- 

 bility, the effects of which R. S. Lillie especially studied" ('i3 3 ). 

 These possibilities were mentioned "in order to point out that 

 the conception" of the fertilizin theory "is not in conflict with 

 the well-established work of others." This is very important 

 for the fertilizin hypothesis is based on certain facts which seem 

 to permit the interpretation given them, and the surface-alter- 

 ation theory also has a verifiable factual basis. These facts, 

 occurrences in and about fertilization, cannot be in conflict with 

 one another. The problem is to understand their interrelations. 

 The experiments on auto-parthenogenesis carry us a step forward 

 in this direction. 



At first sight success in initiating the development of Asterias 

 eggs by means of Arbacia egg-secretion would appear to seal 

 the death-warrant of Lillie's fertilizin theory. On the other 

 hand a little reflection will show that no radical conclusions need 

 be drawn. Parthenogenesis, as is well known can be induced in 

 different eggs by the most diverse means electricity, heat, cold, 

 mechanical shock, osmotic pressure, 2 specific chemical alteration 



1 It would have been more correct to say: it was contained in the egg. 



2 In the case of the purely osmotic methods, Loeb supposes that "the hypertonic 

 solution acts simultaneously in two capacities: first as a cytolytic agent causing a 

 change in the cortical layer (the formation of a gelatinous film) and second, as a 

 corrective agency " ('is 4 . P- 159)- 



The cytolytic action of the hypertonic solution is not without evidence, and so 

 we may consider this method as having the effect common to all the others. If 

 however the increase in permeability is effective also on account of the destruction 

 of the normal fertilization block, in the sense outlined in the text, loss of water by 

 the egg would directly or indirectly accelerate the loss of the antagonists (cp. 

 Glaser, '13, p. 450). 



