BUTTERFLIES OF THE VICINITY OF NEW YORK CITY 
An aberration occurs in the female which is sooty brown, instead of 
yellow, with the black markings faintly visible (var. glaucus). The 
female lays her eggs singly on the upper surface of a leaf, and 
the young caterpillar takes up its abode on the same side, reposing 
on a bed of silk, which it spins for the purpose of retaining its hold 
on the smooth surface of the leaf. When disposed, it goes to the 
edge of the leaf to feed. As the caterpillar increases in size, the 
leaf is somewhat drawn together, making the animal difficult to dis- 
cover. It is green, and has on each side of the third segment an 
irregular oval, greenish-yellow patch edged with black and enclosing 
a purple spot. Atthe junctions of the fifth and sixth segments is a 
transverse, narrow, yellow and black band. It feeds on apple, 
quince, plum, thorn, cherry, birch, basswood, ash, alder, willow, oak, 
tulip-tree etc. 
In the Hall of North American Forestry there is a group showing 
a branch of the tulip-tree bearing male and female butterflies, the 
caterpillar and the chrysalid of this species, and illustrating the effect 
the insect has upon the leaves of the tree. 
2. Black Swallowtail (Papilio asterias). 
Very common in open fields, especially where the wild parsnip 
grows, from May to October, but it is most common in August. 
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