158 BUTTERFLIES 



casing is formed by the exuding from parts of the body of 

 a viscous fluid, which binds together the tender parts and 

 covers the whole with a coating like varnish. This soon 

 hardens and the chrysalis is ready to take its chance 

 against injury." 



The Gray Comma 



Polygonia progne 



This butterfly is rather darker colored, especially on its 

 under side, than the one last discussed. The silver mark- 

 ing takes on a little more definitely the form of an L than 

 a comma, and the under surface of the wings is darkened 

 by many blackish thread-like lines running across the 

 veins. When at rest with wings closed these butterflies are 

 very easily overlooked. 



Except for a diflference in the food plants of the cater- 

 pillar, the life-history of the Gray Comma is very similar 

 to that of the other Comma. The butterflies hibernate, 

 and in spring lay eggs singly on the leaves of currants, 

 gooseberries, and related plants. The eggs soon hatch into 

 caterpillars that feed upon these leaves but do not make 

 any suggestion of a nest. They grow slowly and change 

 into angular chrysalids which disclose the summer brood 

 of butterflies in July. These lay eggs for another brood 

 of caterpillars which mature into butterflies in August and 

 September. These generally go into hibernation before 

 the middle of October, sometimes choosing simply the 

 under side of a branch where their dark coloring, so near 

 like that of the bark, is likely to cause them to be over- 

 looked by their numerous enemies. 



