NYMIMIAUNAK: VANESSA A'lAl.AX'IA. 453 



antennae are .straiii'ht, raised slightly above the plane of the body and 

 spread at about a right angle. When alarmed the wings arc closed back 

 to back with a sudden start. When resting up«»n Howers or the leaves of 

 a tree, the wings are generally held at or very nearly at right angles with 

 each other. \Vhen at rest for the night, the fore wings ai-e as nearly hi<l- 

 den between the closed hind wings as is possible, the costal edge of the 

 former emerging between the tips of the costal an<l upper branch of the 

 subcostal ncrvure of the latter ; the antennae rest against the costsil edges 

 of the hind wings, their tips diverging very slightly. 



Parasites. Not only does a little Trichogramma, T. minutissinunn, in- 

 fest the eggs of this buttcrHv, discovering them during their bi-ief life, and 

 emerging about a fortnight after the time for the cati'ipiliar to hatch, but the 

 caterpillar is sorely beset. First there is a species of Apanteles, A. edward- 

 sii, which must sting the caterpillar before it has completed its very first 

 nest, as Mr. Edwards suggests. Any one that will watch a newly hatched 

 larva will observe its restlessness until its nest is made : Mr. Emerton had 

 exceptional difficulty on this account in making a drawing of it, though 

 many larvae are impatient at this stage. At any rate one may often find the 

 pure white or silvery-gray cocoon of this insect resting beside the larval 

 skin in the nest of the defunct caterpillar, and will find the latter is never 

 beyond the second stage and that one parasite has been enough to kill 

 him. Apparently these parasites sometimes winter in the cocoon. ^Ir. 

 Edwards (1. c. ) gives some account of the action of the species, and found 

 it held in check by a species of Tetrastichus, T. modestus. 



But although in this case a single worm is enough to destroy one cater- 

 pillar, far worse havoc is made among the nettle feeders at a later stage by 

 another species of Apanteles, A. atalantae. It is often difficult to procure 

 a single butterfly from a large number of larvae taken in the open air ; they 

 ai-ecrannned full of these parasitic enemies, which suddenly emerge together 

 through the skin of their victims when full grown, and spin their pure white 

 cocoons beside the now collapsed prey. I first observed them when from 

 some caterpillars of atalanta sent me by Mr. W. Saunders of Ontario and 

 Mr. C. P. Whitney of New Hampshii'e (subsequently raised in numbers 

 by ]\Ir. P. S. Sprague and myself) some pale, dirty yellow, cylindrical 

 worms, 3 nun. long and .7.5 mm. broad, forced their way indiftferently 

 from the back, sides or under surface of the caterpillar, and immediately be- 

 gan to make cocoons for themselves on the nearest spot, the caterpillar itself, 

 and the surface on which it was resting. As the grubs which inhabit a single 

 caterpillar peneti-ate its integument for their change at nearly the same time 

 and in close proximity, their united eftbrts form a net\vork of pure white 

 floss in which the cocoons (88: 13) are enclosed. Generally the mass of 

 cocoons is double, one-half on each side of the caterpillar, which seldom 

 stirs from its position and never far after the emergence of its foes, although 



