The Bionomics of South African Insects. 413 



acridity, and a Coccinellid-like smell in certain species, but 

 even in these the human experience is probably very 

 faint compared to that of a truly insectivorous animal. 

 Nor does it by any means follow that a scent which is 

 excessively unpleasant to man indicates unpalatability to 

 all or even the majority of natural foes, as in the obvious 

 case of Anoplocnemis curvi-pcs, the evil-smelling Coreid 

 bug eaten greedily by baboons (see p. 382), although 

 rejected after tasting by a kestrel (p. 845). Professor 

 Plateau and Professor Wheeler will probably reconsider 

 the significance of their own sense-impressions when they 

 read below that Mr. Marshall could detect nothing un- 

 pleasant in the much-mimicked Limnas chrysvpiyus. 



'^ Est court, Oct. 15, 1896. — I have for some time intended 

 to make experiments on the taste of the Acraeas, . . . 

 However, my tasting experiments have not helped me 

 much, for my sense of taste is evidently not as acute as 

 that of birds and lizards. However, I send you the few 

 notes I have made in case they may be of interest or use. 



" In Acrxa noliara, hcxtoni, cabira, and Plancma csehria, I 

 was unable to detect any trace of bitterness or acridity, 

 and they appeared to me quite insipid ; indeed, as far as 

 mere taste is concerned, I doubt whether I could dis- 

 tinguish them from Bclenois scvcrina, though their outer 

 integuments are much toughei". [Mr. Marshall subsequently 

 found that huxtoni does possess a bitter juice, which 

 exudes freely from the wings when they are cut, especially 

 at the bases,] This alone is sufficient to prove the un- 

 reliability of the test, for cabira is most certainly an 

 inedible species, even if cscbria is doubtful. A. cnccdon 

 and its var. lycia exude a yellow juice from the thorax 

 which is .slightly bitter, but not very markedly so. Acrma 

 anacreon and natalica both exude juice in the same 

 manner, but it seems distinctly more bitter than that of 

 cnccdon. A. anci/wsa in addition to the bitter juice emits 

 a very strong smell when pinched, being the only Acriect 

 in which I have noticed this, though possibly acani does 

 the same, as I regard these as the two best-protected 

 members of the genus. Planema agamcc has no smell, 

 but emits a lot of acrid juice, not only from the thorax, 

 but also from the antennae and the nervules of the hind- 

 wings. With regard to the juice-exuding species I may 

 note that the bitter taste appears to lie only in the 

 exudation and not to permeate the tissues of the body. 



