markinfis and attitudes of leindoptcroiis larvce. 289 



(see fig. 5, rather over natural size). This stage lasts 

 about six days. 



Stage V.— At the beginning of this stage the larva is 

 about 33 mm. long when at rest in a rather contracted 

 state after the effort of ecdysis. This is the last stage, 

 and the larva is, of course, well known. Nevertheless, 

 there are some extremely interesting facts about it, 

 esi^ecially concerning the change from a shagreened to a 

 very smooth larva. Immediately after ecdysis the body 

 is shagreened all over with minute dots, which still 

 terminate in hairs (see fig. 6, Plate VII., natural size). 

 I formerly suggested (in the paper already referred to) 

 that the row of white dots continued anteriorly and 

 inferiorly from the white stripes were the remnants of 

 the shagreen dots. This is now certain, for they have 

 been traced through the ontogeny, and further, even in 

 this stage, each one of them terminates in a minute 

 hair, which is retained to the end. The shagreening 

 very quickly disappears, but it can be detected with a 

 powerful lens, and always remains visible (though very 

 minute) upon the under surface of the body. Although 

 the horn is so smooth and shining in this stage, traces 

 of the tubercles can still be made out. The 8th stripe 

 is always present after ecdysis, but it quickly dis- 

 appears. The deep black of the horn and sides of the 

 head are replaced by dark green after ecdysis, but the 

 latter darkens in a few hours. The shagreening seems 

 to disappear by a change of colour into that of the 

 surrounding ground colour, and a gradual disappearance 

 of the raised eminence which forms each dot. There is 

 the same variability in darkness as shown by the 

 difterent degrees of depth attained by the lower part of 

 the purple border. When this becomes very dark some 

 patches appear on the other (inferior) side of the white 

 stripe. I described this variety last year from a single 

 instance found in the field, but it was quite common 

 among the larva3 reared during the past summer. The 

 larvffi turned brown in many cases on August 21st, this 

 stage having lasted about nine days. Thus the whole 

 larval life lasts about five weeks. There were many 

 exceptions to the periods given for each stage (which 

 were, as far as possible, average instances). 



Summary. — There are many interesting points about 

 this lifc-liistory. Such are the well-developed su])dorsal 

 in the early stages (for the probable existence of which 



