MISCELLANEOUS NOTES. 697 



No, VIII.— NOTE ON THE DURATION OF THE PUPA STAGE IN 

 PAPILIO HECTOR. 



The following note may interest some readers of the Journal :— - 



In August, 1895, I obtained on two or three consecutive days a large 

 number — 50-60 caterpillars— of P. hector, Linnseus. There was not any appre- 

 ciable difEerence in the duration of their lives as caterpillars, and they all 

 changed to pupae as soon as full grown. Though as larvae they seemed exactly 

 similar in every respect, yet the duration of the pupal stage in each varied so 

 widely that of the original fifty pupae — four still remained on March 1, 1896. 

 Of these one came out damaged during the first week in March, two emerged 

 in April, and one in May, the last three being perfect insects. 



It is by no means settled what becomes of the butterflies at certain times of 

 the year, or why some kinds appear in numbers one year and are rare the next. 

 For instance, Euplosa hoUari, Felder, abounded last year in Karwar — though by 

 no means a common insect — and this year, as far as I went, seemed to be a year 

 for Papilio nomius, Esper, At all events I saw many and caught a few, 

 whereas last year, though I was constantly in the jungle, I never saw the 

 insect. What can be the causes which, as in the instance of P. hector I have 

 described, shall delay or accelerate the metamorphoses of a certain number 

 of larvae w^hich as larvae appear in every way similar ? Mine were fed on the 

 same plant, were contemporaries in point of season, and lived in the same cage, 

 in fact all the visible conditions of their existence seemed identical. It is 

 of course, a fact that the season of the year influences the metamorphoses of 

 butterflies, the result being that the majority of each kind appear when their 

 food is at its best ; but it seems to me that, even granting this, the question 

 is not disposed of. To illustrate : — Euthalia laudabilis, Swinhoe, feeds on a 

 well-known evergreen which is apparently in the same condition as to edibility 

 and nutritive power all the year round, I bred many of these insects last 

 year, and observed that, while those bred in the early rains went through 

 their changes with rapidity, a second and later consignment remained as larvfe 

 nearly two months, and the pupal stage was nearly as prolonged, I am told 

 by a learned friend that one was the quick and the other the slow brood, but 

 (with deference) is not this another way of saying the same thing ? 



I have hoard it said that some butterflies may remain dormant in the egg 



stage, but I do not think this hypothesis tenable for the reason that if the 



egg is fertilised before extrusion, then I cannot recall any other instance of 



delay in the developmental changes that take place in a fertilised ovum, 



S, E. PEALL, SuKaEON-CAPTAiN, I.M.S, 

 Bombay, September, 1896, 



No, IX.— FOOD OF THE BULL-FE,OG AND MUSK-RAT. 



If the subject has not become stale, I can add some items to the food of the 

 above-mentioned rapacious reptile and mammal. 



