i9()fi • 125 



be as well to state that the feeding ])eriod of the larva in this latter 

 insect is quite normal : the larva turns transparent green at the end of 

 the feeding (as usual) and in that state lies over, sometimes a short 

 time, sometimes a long time, depending on I know not what causes; 

 is quite active, as it often changes its cell, and never omits to change 

 it just before pupating. 



[This concludes the notes in the first letter, which w^as sent by 

 Mr. Andrewes to Professor Poulton who replied to it direct to Mr. 

 Bell. The second set of notes constitute nearly the whole of Mr. 

 Bell's answer.] 



Thanks for the book containing the different papers ; those 

 African Precis are indeed wonderful in their variety or variation. 

 We have nothing quite as variable as that, except some of the Gato- 

 phaga-Appias lot, which even then only vary from black to white ; 

 nearly quite black all over, however, to nearly pure white ; the black 

 forms being the wet-season ones of course, or the "succulent shoot " 

 forms, which I fancy is the same thing. These shoots come out in end 

 of April and May — which is the hot weather; and dry, and last 

 through the rains. Our Precis, the common one existing right 

 through India into China (now called Junonia iphita), becomes very 

 black (dark brown) in the rains, gets smaller peaks to the wings, that 

 is, the peaks are less accentuated, and besides the tendency to ocella- 

 tion, gets a steely suffusion on the under-side : the only butterfly I 

 am acquainted with that acquires metallic marking. There is another 

 thing, while on Precis, which occurs to me, and that is the rule that 

 the dry forms are the larger does not always apply to Precis, and never 

 to some other species. Por example, the wet-season form of Rypolimnas 

 bolina is more than double the size (wing-area) of the dry-season 

 form ; the same with Hypolimnas ^nisippus, also Cynthia saloma and 

 Cethosia mahratta. Now the reason for this is that the dry-season 

 forms of these butterflies are all more or less starved specimens. 

 The Acanthacece, on which Precis and Rypolimnas feed, and Modecca 

 {Passiflorece, the food-plant of Cynthia and Cethosia) are almost com- 

 pletely wet-season plants, that is they lose their leaves in the dry 

 weather. Barring this starving, all cold-weather forms are larger than 

 the wet-weather ones, and are so, 1 consider, for the reasons I have 

 given before, viz., slower growth due to less " sappy " food. 



In these very damp regions, like Kanara, where the rainfall varies 

 from 100 to 300 inches, the leaves often get spots of white mould on 



