Manh, 1902.] SeIFERT : NORTH AMERICAN ArcTIID/E. 3 



black color on primaries much reduced, the pale bands aiming to 

 unite, bands 2 and 3 often confluent forming with the broad longitu- 

 dinal bands a large median jiatch ; the black maculation on hind 

 wings mostly reduced to mere dots. The black dorsal spots on abdo- 

 men greatly obliterated often only the two faint last ones present; 

 ventrally and laterally the spots diminished likewise. Apparently 

 nothing was gained by the experiment but an extreme southern form 

 of argi'. The females thus obtained deviate from the males in the 

 same manner as if normally developed. The males striving to sim- 

 plify their coloration, while the females, though widening the pale 

 bands also but more reluctantly, at the same time intensify their 

 colors ; the black on fore and hind wings turning deeper and brighter 

 and the salmon red of secondaries spreading and deepening. 



Freshly formed pupte exposed to -+- 4° C. (38° F. ) for thirty days 

 or more, and at once or gradually transferred to normal temperature 

 gave imagines according to the retarding process in about ten days. 



All the moths thus obtained have the black on primaries intensified 

 but rarely more extended than with many of the normal forms, but 

 the secondaries are changed in a remarkable degree. The black macu- 

 lation is enlarged but paler and a dusky or blackish hue cast over 

 the whitish ( <? ) or reddish ( 9 ) color. Contrary to the melanotic 

 form (Standfuss, Handbook), where the darkening process commences 

 from outer margin, the black in the forms by cold is spreading radiate 

 from the base of the wing towards outer margin. Below, basal and 

 median part of wings much obscured by blackish shade. 



The black abdominal spots are confluent to bands ventrally and 

 with some individuals even laterally and dorsally. Even by exposing 

 the pupas to a temperature far below the freezing point for about 24 

 hours the results were practically the same. 



Among the number of specimens thus obtained many attain super- 

 ficially a resemblance to Arctia qucnselii Payk. 



The rearing of progenies of thus changed parents to confirm the 

 transmission of acquired characters (Standfuss, Iris, xii, 1899), have 

 on account of the difficulty in raising the offspring of thus manipu- 

 lated parents been unsuccessful ; the larvae could not be carried beyond 

 4th moult. 



A female changed in the above manner by cold, was exposed 

 August loth (Long Island) and found with atypical male next morn- 

 ing. The brood obtained was a very sensitive one. Part of the 



