T. BrSTORTATA (cREPUSCULARTa) AND T. CREPUSCULARTA (bIUNDULARIa). 217 



T. bistortata, and one would have imagined, had the difference of colour 

 been due to age, that the eggs of T. crcpuscularia would have proved 

 the older. I observed also in the eggs (10 days old) of T. bistortata, 

 which had been fertilised by a (J 2\ biwuhdaria, that the colour was 

 distinctly more yellowish than in the eggs of T. bistortata, which 

 were two days older. The difference here referred to is not the 

 assumption of the yellowish-green tint, which all the eggs take on in 

 a later period of their development, and which is distinctly visible to 

 the naked eye just previous to the final colour change that precedes 

 hatching. 



These notes were written before Dr. Riding's note {ante, pp. 149- 

 150), but at the time that I exhibited these eggs, and made the 

 remarks printed, anf(\ pp. 127-128, I had not learned from Mr. Bacot 

 the age of the eggs. I print this with some diffidence, in the face of 

 Dr. Riding's note, but have no doubt that further observations will 

 make clear the points of difference. 



Notes on Charaxes jasius : its life=history, protective resemblance, 

 etc., witli some observations on moulting and pupation. 



By T. A. CHAPMAN, M.D., F.E.S. 

 {Concluded from p. 194.) 



Physiological notes. — When the larva moults — I had several 

 which changed from the penultimate to the last skin — the head of 

 the larva retreats from the effete head to the pro-thoracic segment, 

 leaving only the mouth parts within the old head ; this is a fact easily 

 observed in many species of larvje, but it struck me here as curious 

 that the four horns or spines of the new head were not directed back- 

 wards, but laterally two to either side, under the skin of the pro- 

 thoracic segment. 



In many Noctuid (and other) larvae with transparent heads, it is 

 easily seen, at the period of moult, that the old head is not entirely 

 filled by the jaws, etc., of the new head, but that the old head is 

 largely occupied by fluid, which bathes the new skin beneath the 

 old one. At this stage the head has really moulted, being chiefly 

 within the pro-thorax. How is the excess of fluid within the old 

 head removed just before the actual casting of the skin — is it swal- 

 lowed by the larva, or does it desiccate ? It can hardly be swallowed, 

 as the mouth is at this period occupied by the effete esophageal 

 membrane. This fluid contains some chitinous matter in solution, 

 and the dampness of the newly-changed larva dries up into a super- 

 ficial layer of chitinous material. The cast skin also, which is damp 

 on being first cast, can, during a brief period after, to be measured 

 by seconds, be extended and displayed ; but if once dried in its 

 shrivelled state, I have always failed by any process to so soften it 

 again as to make it capable of being extended. Some larvfe leave 

 their skins partially extended by all the prolegs retaining their hold 

 of a silken carpet. To return, however, to C. jamm, it may be noted 

 that, as with many other species, in the larval moults, the head is 

 cast entire, but at the pupal moult it splits up. At a larval moult 



