324 Mr. G. A. K. Marshall on 



expected, those species in which the sexes are alike are 

 least edihle. Thus I expect- to find that A. anemosa, A. 

 cahira, and F. aganice will prove more distasteful than 

 their allies in which the sexes differ markedly. However, 

 I must admit that in the case of the Mantis this was not 

 so, and its persistent preference for ccheria rather than 

 Jiorta (on three occasions) is very curious and interesting. 

 Its dislike of the taste of horta was most marked, and yet 

 it did not appear to distinguish it by sight. In Experiment 

 II, c (p. 298) the Mantis certainly avoided Jtorfa after its first 

 taste, but it showed equal fear of ccheria, which it after- 

 wards ate, and I presume could not distinguish between 

 them. But it is clear that it was unable to retain loug 

 the impression which connected a butterfly with an un- 

 pleasant taste. The prompt acceptance of A. sercna by 

 the spiders appears to support my view that the bright red 

 colour conveys no significance to them, although they find 

 the red Iwrta distasteful, I was surprised at their unani- 

 mous refusal of the single specimen of A. violarum I was 

 able to procure, as I had thought it would certainly be 

 more edible than horta, and I am almost inclined to believe 

 that it Avas rejected under a misapprehension, 



I had an idea that perhaps Papilio demodocus was dis- 

 tasteful, which was suggested by its wide range and general 

 abundance ; and that if this were so it would be probable 

 P. 02Jhidice'phalus, P. cwphranor, P. constcmtimts, etc., might 

 obtain protection from their strong resemblance to it on 

 the wing. But my experiments seem to negative the 

 idea as far as invertebrate foes are concerned. 



Again, Terias has always puzzled me. They are so 

 widely distributed and always plentiful; moreover, their 

 flight is weak and their contrasting colours of black and 

 yellow are most conspicuous on the open veldt, which they 

 frequent ; indeed, far more so than the colours of the 

 females oi A. violarum and nohara. Yet they do not seem 

 to be protected, although some of the tropical Durbanias 

 and Tcriomiiihie appear to mimic them, 



Malvern, Natal; Oct. 7, 1897, — The experiments on 

 the effects of an Acrma diet, so far as they go, seem to 

 lend some measure of support to your view as to the un- 

 Avholesome quaUties oi Acr^ea, though many more experi- 

 ments will be necessary to establish it. If I could only 

 get the material I should like to experiment contempora- 

 neously on a number of the same species, starving one, 



