388 OTTO GLASER. 



From these preliminary observations it appeared that the 

 egg-extracts are capable of increasing the permeability of cells. 

 On the view therefore that an increase in permeability is asso- 

 ciated, significantly or otherwise, with fertilization, the initiation 

 of development by means of these extracts should be possible. 

 Against this idea stood the evidence of Loeb ('n) according to 

 which "it was found that it was absolutely impossible to cause 

 membrane formation of the sea-urchin egg by extracts from the 

 sea-urchins of the same or even related species." From this 

 Loeb concluded that the cortical layer of the egg exhibits against 

 the lysins of the body producing it, the immunity characteristic 

 for genetically related cells in general. It seemed little likely 

 therefore that extracts prepared from the cells themselves should 

 result in the initiation of development, and as a matter of fact, 

 "membrane formation" in the sea-urchin egg did not occur. 

 On the other hand, in corresponding experiments on the eggs of 

 Asterias, a typical fertilization membrane did appear, and in 

 both sea urchin and starfish, development was successfully 

 initiated. For the type of initiation here dealt with, I have 

 chosen the term auto-parthenogenesis. 



AUTO-PARTHENOGENESIS IN Arbacia BY MEANS OF EGG- 

 SECRETION. 



The solutions employed in these early experiments, despite 

 the use of weighed quantities of eggs, were not only very variable 

 in concentration, but also differed in composition according to 

 the method of preparation ('i4 2 ). Since the secretion from un- 

 fertilized eggs, has the same effects on sperm as the extracts, it 

 appeared possible that it might also have similar effects on 

 blastulse, Arenicola larvae, and unfertilized ova. This indeed 

 was soon found to be the case, although as pointed out elsewhere 

 ('i4 2 ) extract and secretion are probably not identical throughout. 



The next step, the discovery of a more reliable mode of pro- 

 cedure, resulted in a definite method of securing results, but I 

 have no reason for considering it final. Omitting the experi- 

 ments of orientation and other unnecessary details, the following 

 outline may be taken as a guide for further work: Standard 

 secretion was prepared by adding to a certain number of "dry" 



