markings and attitudes of lepidoptcrons lanue. 283 



in the case of the two upper rows, where there is only 

 one hair to each row on each segment). The head is 

 thinly covered with similar hairs. 



In addition to these long hairs there must be a com- 

 paratively thick coating of much smaller ones. I was 

 able to prove their existence at a later date by the use 

 of the compound microscope, or even by a powerful 

 hand lens ; but I was away from home and without a 

 sufficiency of appliances when the larvae were in the 

 first stage. There can be no doubt of their presence, 

 and they cover the horn as well as the body. The two 

 bristles forming the terminal prong are also hairs. The 

 mandibles are green with the cutting edges black : the 

 ocelli are black and distinct. The spiracles are hard to 

 make out, and the dorsal vessel is visible but not 

 distinct. The head is rounded and of a generalised 

 larval shape and not Sj^hinx-like. The horn is flexible 

 and movable. It soon becomes straight, and may be 

 held at an angle or parallel with the back. The young 

 larvse spin webs for foot-hold, and readily suspend them- 

 selves by threads. This fact has already been observed 

 by Kleemann, and it is very interesting, as the habit is 

 so entirely abandoned later, although it appears again 

 before pupation. The disappearance of this habit pro- 

 bably follows from the great size and weight of the 

 larva, which render this method of attachment and 

 suspension comparatively useless. It is of especial use 

 when the larva clings to the flat under side of the leaf 

 at any point except (that usually selected) the projecting 

 midrib. Later the larva gains security by the extreme 

 power of its claspers. A similar change of habit is better 

 seen in the larva of Dicranura vinula, because here the 

 presence of the web exactly corresponds to foot-hold 

 upon the leaf. It is to be noted, however, that this 

 larva does not lose the habit to the same extent as 

 S. ligustri (or S. ocellatus), and that when young it 

 clings to the smooth upper surface of the leaf. The 

 protective resemblance is to the under side of the leaf, 

 and the larvae are especially hard to distinguish when 

 seated on the midrib, and in this position they seem 

 nearly always to rest. The dorsal vessel becomes very 

 distinct after the larvae have fed for a short time, and 

 the tracheal system is visible. The larva becomes 

 greener, and the first trace of marking appears with the 

 formation of a white circular patch round the base of 



