186 BUTTERFLIES 



the woods. One is the familiar Mourning-cloak and the 

 other is the Compton Tortoise — the latter generally much 

 less abundant than the former. Both make the most of 

 the brief periods of sunshine and quickly disappear when 

 the sky is overcast. 



The Compton Tortoise butterflies which are thus abroad 

 in early spring have been in hibernation since October. 

 They are helping to carry the species over from one season 

 to another, and as the days become longer and warmer 

 they appear on the wing more and more, seeking such 

 liquid food as the field and forest yields during the days of 

 early spring. The sap exuding from holes in bark made by 

 woodpeckers, or from the tappings of the maple trees by 

 man, the nectar of willow catkins, the moisture of road- 

 side pools — ^these help to yield a precarious sustenance to 

 these butterflies after their long winter fast. They remain 

 upon the wing week after week, while spring slowly pro- 

 gresses in the northern regions they inhabit. When at 

 last the leaves push out on their food trees — willow, birch, 

 and elm — the females lay their eggs and then, having 

 lived to what for a butterfly is a ripe old age, they die, 

 after nearly ten months of adult existence. 



Apparently the eggs are laid in clusters on the twigs, al- 

 though this seems to be one of the many facts about but- 

 terflies awaiting observation by some careful student. 

 The caterpillars feed together in small colonies but make no 

 nest. They become full grown in about a month. They 

 are then nearly two inches long with spinous, greenish 

 bodies, striped with lighter lines. Some change to chrys- 

 alids about the middle of June and ten days later change 

 again to butterflies, the first of which appear early in July 

 while others continue to emerge for nearly a month. 



