20 



Experimental Zoology 



tional form like Fig. 3 ; one form, the aberration artermis, 

 with many groups of golden scales on the brown ground color 

 and the black border, and even within the blue spots; the rest 

 for the most part belonged to the aberration hygiaea, one of 

 these being as extreme a form as that shown in Fig. 8. 



The under side of the 

 wings of these butterflies 

 is also changed, but not 

 always in the same way as 

 the upper side. As shown 

 in Fig. 10, not only does 

 the yellow border of the 

 wing extend inward, as it 

 does also on the upper side, 

 but at the same time the 

 black scales spread toward 

 the periphery, darkening 

 the broader yellow band, as 

 shown in Fig. 10. This 

 figure shows the under side 

 of the aberration hygiaea. 

 In the butterfly shown in 

 Fig. II the whole under 

 side is black, the yellow 

 border having disappeared. 

 This is the under side of 

 the butterfly shown in Fig. 

 8 that had the broadest 

 development of the yellow 

 band on the upper side. 



Some further details may 

 now be considered. Merri- 

 field did not employ very ex- 

 treme temperatures. The pupae were either iced {t^t^'^ F.) or only 

 cooled (39° to 57° F.). For " forcing," temperatures not higher 

 than 70° to 80° F.J or even 90° F., were employed. He found 



Fig. 3. Vanessa antiopa, under surface 

 Figs. 9-1 1 showing influence of cold 

 (After Fischer.) 



