24 PYRALIS GLAUCINALIS. 



branches on birch trees might perhaps be tenanted 

 by some larvae or pupae, I obtained one of these knots 

 in April, 1867, and placed it in a large breeding cage, 

 where I soon observed a few black active-looking 

 larvae, and some old cocoons containing empty pupa- 

 skins. 



" Having no conjecture as to what species these 

 belonged to, I was much interested by observing on 

 the 10th of June a specimen of Pyralis glancinalis at 

 the side of the breeding cage; others continued to 

 appear, and on the 13th of June I find a note in my 

 diary, ' Larvse, pupae, and imago of glaucinalis all alive 

 at same time.' 



" On the 24th of June I took out the knot, and 

 by shaking and beating it obtained from it twelve 

 specimens, which were by no means easily dislodged. 



" The species continued to appear throughout June 

 and part of July, till about forty specimens in all were 

 bred from this one large birch knot. 



" This year (1869) I again obtained knots from the 

 same locality as before, and found them to contain 

 old cocoons, and larvae of the same species in various 

 stages of growth ; from these I bred a few specimens 

 of the perfect insect about the middle of July. 



" The clean white silken cocoon is semi-transparent, 

 and of a texture which strongly reminds one of the 

 skin immediately beneath the shell of an egg, only 

 that the silk is less opaque; it is placed among the 

 twigs towards the centre of the branch, but not 

 attached to them, although the webs of the larvae 

 among the frass, and also of the numerous spiders 

 which it contains, prevent the possibility of shaking it 

 out ; in spite of this, however, it is always quite clean." 



On the 18th of April, 1869, Mr. de Grey kindly 

 sent me several larvae with their food — that is to say, 

 a mixed mass of birch twigs, decomposed leaves, and 

 earthy matter containing many old cocoons and pupa- 

 cases, some small tufts of sheep's wool, and an old 

 gun-wad. 



