]^98 [February, 



top of its cocoon covering, and inspects the strength, durability, and 

 finish of its work, and may be seen spinning additional threads to such 

 parts as require strengthening. "Whilst thus occupied, we may observe 

 that a vacant space is left in the centre of the cocoon covering, which 

 space had been occupied by the body of the larva whilst at work. 

 I apprehend this covering is only spun with the object of further 

 indenting the leaf, so as to make it more suitable for the reception of 

 the oval cocoon, as I have observed that when the larva makes its 

 cocoon in the angle formed by the top and side of a box-lid, it often 

 forms it without any covering whatever. 



The larva now retires backwards through this identical opening on 

 the cocoon canopy, which it does not trouble itself to close, and at once 

 turning on its back, begins the construction of its cocoon proper directly 

 beneath, but not attached to, the upper canopy; in this position 

 it works away, spinning and carrying silken threads from side to 

 side till it has formed the cocoon ; it then turns over on to its feet and 

 spins a white silken band all round the inner margin of its partially 

 completed cocoon. 



"When I first perceived the silken band I conjectured that its 

 object was to keep the larva snug and warm during the winter months, 

 but, as I find that the summer broods of the larvae construct similar 

 silken bands, this can harly be the object. 



In the subterranean cocoons I do not perceive any silken band, or 

 anything analogous. "When the band is complete the larva sets to 

 work to carpet the floor of the cocoon with white silk, as a soft couch 

 on which to recline ; it then again turns on its back, and continues 

 actively employed in spinning additions to its cocoon, until this 

 at last becomes so opaque that the movements within are no longer 

 perceptible. 



The time occupied by the larva in the construction of its cocoon 

 is between nine and ten hours — hours of almost incessant labour. If 

 turned out of its cocoon directly it is finished, the larva sets to work 

 and constructs another cocoon complete in every respect like the first, 

 but if it be again ejected after fabricating its second cocoon, its supply 

 of silk being quite exhausted, it lies perfectly helpless, and a larva so 

 treated very often dies, not having even strength to assume the pupa 

 state. 



If the larva be left undisturbed iu its cocoon, its body soon becomes 

 quite white, and a death-like trance steals over it (it may then be 

 handled or turned about without its showing any power of movement), 



