Insects. 



8785 



variety, distinguishable even from the egg, which is pink instead of red. From these 

 lighter eggs the larva) produced have, throughout their earliest stages, a reddish tint in 

 those parts of the body where the other specimens are black; and after the last change 

 of skin they are lighter than the others, both in the ground colour and the shadings. 

 Does this produce the variety of the moth once isolated as D. erminea ? These larvae 

 were fed both on willow and poplar, but the poplar seemed to be the most congenial 

 food, and the largest in growth were fed exclusively upon it. They were supplied with 

 fresh leaves twice a day, at 8 a. m. and 6 p. m., and really appeared to manifest some 

 dim consciousness of the approach of feeding time, even when their slock of food was 

 not exhausted, although they certainly did not display the restless agitation which the 

 accustomed hour provokes in the captive Carnivora. At each successive change of 

 skin the larva devours the cast-otf garment, with the exception of the head, which seems 

 too tough a morsel. The time occupied by each change is usually four days, and the 

 larva eats nothing for about half a day after it is completed (saving the old skin). 

 These larvae are remarkably pugnacious after they have changed their skins for the 

 last time, the approach of an observer immediately occasioning the protrusion of the 

 tentacula or inner horns. As they increase in size they become more pacific. These 

 larvae have, as most entomologists have observed, the power of ejecting a fluid in 

 defence when annoyed or irritated. Old writers on Natural History state that thia 

 fluid is thrown from a rose-coloured aperture behind the head. On the contrary it is 

 below the head, extending, when the larvae are full-grown, transversely about two lines, 

 just beneath the chin, if one might so call it. Rennie says that this power of ejection 

 is lost when the larvae are removed from their parent tree. This is the case with most, 

 but singularly enough not with all ; three of those I had were exceptions to this rule. 

 This liquid is of an acrimonious nature, probably containing an acid. A large pro- 

 portion of the larvae lost one or both of their " horns " or " tail appendages " from a 

 curious cause. They appear to be reckoned tit-bits by some individuals, and when 

 they could do so successfully they employed their jaws in nibbling off the posterior 

 ornaments of their companions. This strange propensity was not occasioned by any 

 scarcity of their accustomed food. The larvse, however, when awake are peculiarly 

 sensitive to any attacks of this kind, and T noticed that these approaches were only 

 successful at times when the individual attacked was in a state of repose. I use the 

 word " awake " advisedly, for from my observations made upon many species of lepi- 

 dopterous larvae, I feel convinced that they do sleep at times, or something very nearly 

 analogous to it. This same propensity manifested itself in a brood of Smerinthus ocel- 

 latus, half of which had the posterior horn nibbled off. When the larvae of D. vinula are 

 about to cease eating and form their cocoons the whole ground colour changes to a dull 

 brown. I was anxious to ascertain whether any two of the larvae, who were seeking at 

 the same time for a convenient spot to form their cocoons, would unite and form a 

 common one, as sometimes occurs with the silk-producing larvae : no such instauce 

 occurred. They seemed, however, fond of forming their cocoons upon those of their 

 predecessors. In one corner of a box I have no less than six clustered together. Several 

 larvae ornamented their cocoons by interweaving some of the excreta, or " caterpillar's 

 pills" as a juvenile friend calls them, thus presenting rather an odd appearance when 

 finished. — John R. S. Clifford ; 21, Robert Terrace, King's Road, Chelsea, September 

 14, 1863. 



Description of the Larva of Clostera curtula. — The eggs of the first brood are usually 

 laid during the month of April, on the bark of Sulix capraea (sallow), Populus tremula 

 VOL. XXI. 3 P 



