184 BUTTERFLIES 



The Story of Its Life 



In its manner of laying eggs this butterfly differs from 

 most others. The great majority of om* famihar species 

 lay their eggs one in a place or possibly two or three near 

 together. Some species deposit several in a group, while 

 some, like the Mourning-cloak, may lay two or three dozen 

 in a cluster. Very few, however, deposit hundreds in a 

 bunch. Two of these are the Baltimore and this American 

 Tortoise-shell. In the case of the latter the eggs are 

 loosely laid, hundreds together, upon the leaves of the 

 common stinging nettle. Probably each female can de- 

 posit six or eight hundred eggs. In less than a week the 

 eggs hatch into minute blackish caterpillars that feed upon 

 the tender tissues of the leaf upon which they were born and 

 then migrate together toward the top of the plant. In 

 their habits they are quite similar to the caterpillars of the 

 Mourning-cloak. As each walks it spins from its mouth a 

 silken thread and the combined effect of hundreds of these 

 threads is to make a noticeable silken web over the leaves. 

 The caterpillars remain in colonies, feeding together from 

 day to day and gradually denuding the upper branches of 

 the nettle plant, leaving an unsightly silken web as a 

 memento of their presence. This webbing is very sug- 

 gestive of the similar result left behind by a colony of 

 Mourning-cloak caterpillars upon the twigs of elm or 

 poplar. 



When about half grown these caterpillars are likely to 

 scatter more or less in accidental groups which may make 

 small shelter tents from the larger leaves. In each little 

 nest there may be four or five or more of the dark-colored 

 caterpillars. From these shelter tents they sally forth to 



