The Bionomics of South African Insects. 81 9 



IV., the deformity of VII., while III. was released. 

 Experiments V. and VIII. were also upon the same 

 species of Mantis. The first, a male, became weak and 

 probably blind after eating a few Acrasas ; the second, a 

 female, remained apparently healthy after an exclusively 

 Acroeine diet for fouiteen days. It is very unfortunate that 

 this latter experiment could not be continued. It is, 

 however, clear that in the case of this species and sex a 

 purely Acroeine diet for fourteen days is not necessarily 

 unwholesome. Experiments IX., X., and XI. were upon 

 species which were the same, or nearly the same, and all 

 females. The first died after an Aciwa diet for twenty 

 days, the second was perfectly healthy after a mixed butter- 

 fly diet without Acrxioi/e and Danainm for fifteen days, 

 while the third lived healthily from April 3 to September 8 

 upon Acra3as and Limnas clirysippus. The latter seems to 

 be an insuperable difficulty, but it must be remembered (1) 

 that chrysippus was given in especially large numbers, and 

 there is no evidence that Danainm are much rejected by 

 MantidcV, (2) that the Mantis may have recovered from 

 the effect of the Acrasas during the long fasts, (3) that the 

 Acrxa chiefly made use of, A. caldarcna, may be less 

 unwholesome than the majority of the group. 



More experiments are greatly wanted, but Mr. Marshall's 

 observations render it highly probable that Acrseas are 

 unwholesome to ManticLv. The definiteness of the 

 symptoms exhibited, and especially the effect upon the 

 eye, constitute not unimportant evidence in support of 

 this conclusion. The appearance of an opaque blotch in 

 the left eye of three of the Mantises (V., VIL, IX.) suggests 

 farther experiments in order to test whether we have to 

 do with mere coincidence or a phenomenon of deeper 

 significance. 



Mr. Marshall's conclusions from his experiments were 

 written upon the results obtained with spiders as well as 

 Mantises, and will be found at the end of the section upon 

 the former (p. 322). 



4. Experiments on Spiders in the Karkloof. 

 (G. A. K. M.) Natal, February 1897. 

 [The Rev. O. Pickard-Cambridge, F.R.S., informs me 

 that the species made use of was the common and widely- 

 distributed Epeirid Nephilengys malabarensis, Walck. — 

 E. B. P.] 



