34 LExperinental Zoology 
Pictet has also tried the effects of insufficient nourishment, 
using smaller amounts of the normal food. In the case of 
Pieris crategi, lack of food during the last days of the life of 
the caterpillar causes the wings to become lighter in color and 
more transparent. If all food is removed from the full-grown 
Fic. 5. Psiluria monacha: typicai male, Fig. 10; and female, Fig. 11. Aber- 
rant form P. ingra: male, Fig. 12; female, Fig. 13. Aberrant form P. eremita: 
male, lig. 14; female, Fig. 15. (After Pictet.) 
caterpillar of Vanessa urtice, it becomes a chrysalid in a few 
days after the last moult. The butterflies are dwarfs, but show 
no changes in coloration. On the other hand, if the very young 
caterpillars are kept on a régime that becomes less sufficient 
every day, they become pupe even before the last moult, and 
produce dwarf butterflies that have the aberrant characters 
much accentuated. 
