44 Mr. E. B. Poulton's notes u/pon the colours 



affording a great unlikeness to organic form as assumed 

 in this division of the animal kingdom. 



(There is often the additional protection of distinct 

 likeness to some object which could be of no interest to 

 the enemies of the larva). 



Hence the not infrequent position of some structure 

 on the convex side of a bend producing the effect of 

 an angle. A most remarkable instance of this is seen 

 in the attitude of N. ziczac, the name of which indi- 

 cates that entomologists have been deceived as to the 

 true position of the larva when at rest. This caterpillar 

 throws itself into a series of undulations in the vertical 

 plane, of which the bends are perfectly round and even, 

 and yet by a structure to point each curve the appear- 

 ance of an angular zigzag is produced. 



The following is an account of the series of bends 

 with the structures situated upon each : — The head and two 

 succeeding segments are thrown backwards, producing a 

 curve with the proximal part of the body. The 4th 

 segment is in the centre of this curve, of which the 

 convex side is, of course, situated ventrally, and it is 

 distinctly pointed by the 3rd pair of true legs, which are 

 held out straight in the protective position, and at once 

 attract attention. The centre of the next bend (in the op- 

 posite direction) is the 6th segment, and its convex dorsal 

 side is rendered very prominent by a large hump, which 

 in this attitude completely dwarfs that on the 7th seg- 

 ment. The convex side of the next bend (in the 10th 

 segment) is pointed by the 4th pair of claspers, which 

 are held so as to be very conspicuous, and further attract 

 notice by their strongly contrasted colours. The 2nd 

 and 3rd pair of claspers have slight traces of a light 

 longitudinal stripe, but the 4th has so large a stripe as 

 to convey the impression that the lateral (spiracular) 

 line is turned aside into it. Careful examination, how- 

 ever, shows that this is not the case, for the line can 

 just be detected posteriorly to this point. The wide light 

 stripe on the 4th pair of claspers also gains in prominence 

 by the presence of another dark marking sharply con- 

 trasted with it, the two opposite shades of colour meeting 

 in an abruj)t line of demarcation, which traverses the 

 external side of the clasper longitudinally. The dark 

 stripe does not occur on the other claspers, and it is 

 continued on to the posterior part of the 4th pair from 

 the clouded orange-colour upon the 11th and 12th seg- 

 ments, of which colour it shows the deepest shade. It 



