3O HARRIETT M. ALLYN. 



the egg as normally. The result may be complicated by the 

 fact that a small amount of body fluid is always present, and 

 does not mix with the oil. However, where the eggs seemed to be 

 comparatively free from body fluid in the oil, the results were as. 

 stated. It is possible that the space between the membrane 

 and the egg may be obliterated by the swelling of the egg. 



E. Cane Sugar Solutions.- n, 5/8, and n/2 solutions of cane 

 sugar were tried. All of the solutions injured the eggs consider- 

 ably. In the 5/8n sugar the membrane swelled away from the 

 egg, leaving a space much larger than normal, while the egg itself 

 appeared to be plasmolyzed. Evidently fluid had been extracted 

 from the egg into the vitelline space by the injurious action of the 

 sugar solution. In a few eggs in all the solutions the germinal 

 vesicle broke down, its contents migrated to the animal pole, 

 and something resembling an abnormal polar spindle was formed. 



The experiments are too few to draw from them definitive 

 conclusions. It seems possible, however, that the internal con- 

 dition of the egg is a sufficient stimulus to cause the first develop- 

 mental stage, provided that conditions be furnished which are 

 favorable to the reactions involved, that is, that the egg needs no 

 stimulus from without, and that the failure of the germinal 

 vesicle to break down in the ovary is due merely to an inhibition 

 of the processes because of a lack of favorable conditions in the 

 ovary. that all that is necessary is a release of the process in 

 the egg. 



III. STUDY OF ARTIFICIAL PARTHENOGENESIS IN CH^ETOPTERUS 

 BY MEANS OF SINGLE AGENTS. 



A . The Action of Salt Solutions. I . Potassium Chloride. Mead 

 ('98), Loeb ('oi) and F. R. Lillie ('02) used potassium chloride 

 to induce development in Ch&topterus, Mead only carrying the 

 eggs through maturation and a few of the earlier developmental 

 changes, Loeb performing a number of experiments to determine 

 the nature of the KC1 effect, and Lillie making an extensive study 

 of the course of the development, with living and fixed material. 

 Following their lead I have used potassium chloride as one of my 

 principal agents. The cytological results of potassium chloride 

 treatment are very interesting and appear fairly typical of 



