152 Staten Island Association of Arts and Sciences 



variations and aberrations result directly from the food plants, 

 etc., I may cite Dr. Paul Salowiou, of Warsaw, whose experi- 

 ments with pupae of Vanessa urticce, subjected to poisonous 

 fumes or directly brought into contact with different poisonous 

 substances, are here summarized. 



Pupae painted with tincture of iodine — all died. 



Pupae kept in sulphur powder — all emerged normal. 



Pupae subjected to the fumes of sulphuric ether — all died. 



Pupae subjected to the fumes of oil of mustard — all died. 



Pupae left in water twenty hours — all died. 



Pupae coated with ink — all emerged normal. 



Pupae laid in salt — emerged normal. 



Pupae placed in caustic ammonia — emerged normal. 



Pupae subjected to ammonia fumes — partly died and partly 

 emerged normal. 



Of all the above trials not a single instance is recorded 

 crowned with success. 



In the experiments of Dr. H. Auel and E. Gerwin on Psilura 

 monacha the theory advanced is that monacha was originally 

 white, like its near allies, but by gradual evolution attained its 

 present form. Experiments with food plants such as oak, pine, 

 linden, elm, produced normal forms while individuals raised on 

 nut trees, especially walnut, displayed decided variation into 

 melanic or darker forms, in one special case almost black. Auel 

 goes further in claiming that the dark forms bred true exclu- 

 sively, but he does not state whether the larvae were again raised 

 on walnut, the same food plant, or not. Nor is Auel alone in 

 this observation, as even Dr. Standfuss claims hereditary con- 

 ditions for melanic forms. 



Otto Meissner, of Dresden, thinks that more aberrations are 

 observed near the larger cities than in the open country. He 

 further claims that sulphuric acid, produced by the burning of 

 hard coal, is responsible, in his estimation, for this fact. Dr. 

 Karl Flach, by experiments, in overfeeding and underfeeding 

 various Saturnidae (Satumia pavonia, S. pyri, Samia cecropia), 



