THE ENTOMOLOGIST. 57 



throws off its tegument for the second time, its markings 

 gradually re-appearing. The larva has a natural repugnance 

 to feed in au exposed position, preferring to keep as much as 

 possible on the under side of its various food-plants : this 

 habit will in a measure perhaps explain the reason of our 

 meeting with them so much more abundantly on the leaves of 

 Heracleum Sphondylium than most of the other umbelliferous 

 plants that they affect ; the large size of its leaves affording 

 them greater privacy, and exposing them less to the prying 

 eyes of their enemies, birds and Ichneumons. As an out-of- 

 doors feeder it only consumes the outer fleshy covering of the 

 under side of its food, but when confined in the breeding- 

 cage it feeds indifferently on both sides of its food-plants. 

 The larva3 are of a most sociable nature, for, although I have 

 purposely crowded them to excess, I have been unable as yet 

 to discover any trace of unfriendliness towards each other. 

 At intervals they leave off feeding and lay about on the food 

 in a listless manner, and after a few hours fast, the white 

 colour of the dorsal vessel nearly disappears, the fluid situate 

 at its sides very frequently entirely disappearing, and re- 

 appearing when the creature renews its feeding : this dorsal 

 fluid is subject to changes of colour, at one time being dull 

 brownish, deepening to a somewhat slate-colour, and at others 

 it has a dull greenish tinge. Some of these larvae when 

 offered leaves of Chaerophyllum temulentum ate large pieces 

 out of them, yet when these self-same larvae were removed 

 on to plants of Daucus carota,Torilis anthriscus and Anthriscus 

 sylvestris, they only skeletonized the leaves ; and further, when 

 a small portion of a leaf of Heracleum Sphondylium was 

 placed in the breeding-cage along with them, a few hours 

 afterwards they were nearly all observed to have forsaken the 

 other plants to feed on the Heracleum. I believe that the 

 larva moults three times, but that it has escaped my notice. 

 On the larva's arrival at maturity the coloured fluids retire from 

 its dorsal vessel, leaving the body of a yellowish white tint. 



The larva thus constructs its open net-work cocoon. 

 The silk of which this pupal abode is composed would ap- 

 pear to be entirely free from silken globules, and through the 

 meshes of its cocoon the larva is distinctly visible. During 

 this part of its larval and the whole of its pupal state, privacy 

 it would appear is so essentially necessary for the creature's 



