markings and aititiides of lepidopterons larv<e. 311 



is a small tubercle with a few prominent hairs on each 

 side of and above the anus. The spiracles cannot be 

 distinguished with the naked eye. After twenty-four 

 hours' feeding the larvfe are about 4 mm. long, and they 

 are not quite so stout [>roportionately. When disturbed 

 they now let themselves down with a thread. In the 

 bent-up (U-like) attitude a slight lateral bend of the 

 head is sometimes seen. This is an interesting fact, as 

 it exhibits a tendency towards the greater asymmetry 

 afterwards more commonly observed. A light line now 

 appears on the sides of the three thoracic segments, 

 and the white markings of the four bands at the same 

 level appear to continue this line backwards as an 

 interrupted spiracular line. There are traces of a fifth 

 band between the 5th and 6th abdominal segments. 

 The anterior band is, as before, far more distinct than 

 the others. The light ground colour which appeared 

 anteriorly and posteriorly in some specimens has 

 now generally darkened. This seems to take place 

 directly after feeding for the first time. In two days 

 the length is 5 mm., and the larva is very uniformly 

 cylindrical. There is no change in the markings or 

 habits. A little later the ground colour of the larvae 

 becomes less black, though still remaining dark. In six 

 days the larvae are about 7 mm. long, and in nine days 

 most of them (eight out of twelve) changed their skins 

 for the first time. 



Stage II. — (See fig. 16, x 2, Plate VII.). I was not able 

 to observe whether the skins were eaten, but this is pro- 

 babl}^ the case, as no traces of the cast skins could be 

 found. In this and succeeding stages the same lateral 

 movements occur, although they are less often seen after 

 the second stage. The larvae are stout and about 8 mm. 

 long at the beginning of this stage. During rest the head 

 (which is unchanged in colour and shape, except for 

 a little flattening) and two anterior thoracic segments 

 are bent backwards, and the bend pointed and made 

 apparently angular by the 3rd pair of true legs, which 

 are held out straight. Thus this position is assumed 

 before the appearance of the ridge bearing the 3rd pair 

 of true legs in later stages, which makes the same 

 attitude so much more irregular and effective. The 

 irregular spiral attitude is also often seen in this stage, 

 and when this is the case the head and two anterior 

 thoracic segments are bent on one side as well as 



