ARTIFICIAL PARTHENOGENESIS IN THE SILKWORM. 21 



beyond thirty per centum, and was usually not more than twenty 

 or twenty-five per centum. The eggs treated with concentrated 

 acids for the shorter periods, i. e., one fourth and one half minute, 

 were in better condition than those treated for one or two minutes. 

 The eggs treated with ten per centum hydrochloric acid showed 

 no special stimulation. 



Treatment with Absolute Alcohol. — Killed the eggs. 



Treatment with Potassium Hydroxide — Eleven lots of unferti- 

 lized eggs treated with strong solution of potassium hydroxide 

 for periods ranging from one fourth minute to two minutes. All 

 the eggs treated were loosened from their resting place and soon 

 collapsed. Before dying the eggs showed a reddish color like the 

 normal cherry of developing eggs, but from the great prevalence 

 of this color in all the treated lots and parts of lots I am inclined 

 to believe this color due to some special effect of the reagent on 

 the egg shell rather than the indication of development. In the 

 lots treated with strong solution for two minutes death and collaps- 

 ing soon occurred, and in the lots and parts of lots treated for 

 one fourth minute with half strength solution, collapsing occurred 

 before it did in untreated lots and parts of lots. 



Treatment with Lime Water. — Five lots of unfertilized eggs 

 were treated with saturated lime water for periods varying from 

 three minutes to one hour. No increase in proportion of de- 

 veloping eggs. The eggs of a fertilized lot treated with lime 

 water for three minutes ; all (except the small normal per centum) 

 developed and hatched. 



Treatment with Glacial Acetic Acid. — Seven unfertilized lots 

 treated with glacial acetic acid, strong and half strong, for periods 

 of one minute. Behavior of the lots uneven. In three of the 

 lots no stimulating effect was noticeable. In two about ten per 

 centum of the eggs developed. In one about thirty per centum 

 began development, while in lot 7, a lot of three hundred and 

 twenty-five eggs, half of which were treated and half left untreated 

 more than fifty per centum of the treated eggs began develop- 

 ment, while in the untreated lot very few, not more than two per 

 centum. In a fertilized lot treated with the acid for one minute, 

 all the eggs, except four or five, developed and hatched. 



Treatment with Ammonium Hydroxide. — Six unfertilized lots 



