PROTECTIVE DEVICES IX BASILARCIIIA. 265 



is of a dark green or greenish brown color varied with cream coh)r, and 

 smooth as if varnished. This makes it appear like a hanging lump of 

 bird dung, and so again must often prevent its being picked off and 

 devoured by some hungry bird. 



When one that has at last escaped all the perils of its youth finally 

 reaches its full development, it is even more conspicuous and exposed than 

 before. Although now upon the wing and no douljt often able to escape 

 a pursuer by some quick movement, its natural flight is not swift, and its 

 ordinary movements on the wing are a few quick flutters followed by a 

 sailing motion which is most favorable to capture. Its colors difTer of 

 course in the different kinds, and they may in this particular be divided 

 into two classes. One affects a deep rich black-blue or blackish purple, 

 and is variegated with light blue and white, the latter partly in the form of 

 bands, on some forming a broad bow across both wings, rendering them 

 most conspicuous and striking objects. They are, too, of a pretty large 

 size, and as they fly mostly in the neighborhood of copses or along shaded 

 roadsides or forest roads, they seem to render themselves by the contrasting 

 back-ground as conspicuous as possible. Another class is of an orano-e 

 brown color of greater or less depth, while the veins are Ijlack, and a black 

 stripe, sometimes accompanied by white dots, crosses the wings. These 

 fly in more open places, more fully exposed to the sun and are scarcely 

 less conspicuous than their fellows. All these butterflies live a consider- 

 able time, and indeed the eggs do not mature in the bodies of the females 

 until they have been a fortnight on the wing ; and then they do not lay all 

 their eggs at once, or even within a few days, but prolong the operation 

 over many days or even several weeks. To deposit all her eggs therefore, 

 which is the province of course of the female, she must fly amid all the 

 dangers her conspicuous colors offer for about a month, a considerably 

 longer time than the average of butterflies. Previous to egg-layino- at 

 least, much of her time is spent upon the ground in company with her 

 fellows, often in great flocks, engrossed in sucking up moisture from the 

 damp earth, from decaying fruits or the droppings of beasts ; and so nuist 

 become a conspicuous and easy prey to her enemies. 



What then is to become of this saving remnant of the tribe? How 

 escape from the dangers which it seems to invite? For the individual 

 there would seem to be nothing but chance ; but the number of eggs laid 

 under the most favorable circumstances or chances is very considerable ; 

 and if only a pair of these finally reaches maturity and is able to fulfil its 

 functions, the number of individuals of the species is maintained. It 

 would seem, however, as if even this chance were small and as if still 

 further protection were needed. And one further protection seems to be 

 afforded in some species in a j)eculiarity of their life history. Apparently 

 the species of Basilarchia are, at least in New England, normally single 



