18 SAVAGE SUDAN 



Moisture in arid Africa, however exiguous/forms a veritable 

 lodestone to the insect-world as to every other. Wherever 

 the tiniest tricklet provides moistened margins, thereat will be 

 found assembled swarms of bright-winged butterflies small 

 blues and brimstones chiefly which rise at one's feet in clouds ; 

 though elsewhere never another will be seen in a long day's 

 march. Even blood appeals. It is striking not to say 

 revolting when some big beast is being "gralloched," to 

 watch these delicate beauties assembling to revel in gore. 



Many butterflies assimilate in marvellous degree with the 

 surfaces upon which they habitually alight. There is in Africa 

 a speckled brown species, not unlike our wood-argus (Hipparchia 

 cegerid) but " mud-coloured " on both surfaces to perfection, and 

 it invariably settles on bare mud ! Still more accentuated is 

 this assimilation in the under-surfaces of very many butterflies. 

 These facts are patent even to superficial observation ; but the 

 deduction that assigns their origin to "colour-protection" is 

 probably no less superficial. Against what enemies are butter- 

 flies assumed to be " protected " ? 



In his African Nature Notes (1908), SELOUS first pointed 

 out that birds, as a rule, do not prey on butterflies or, to be 

 more precise, that during his lifelong experience in Africa he 

 had never seen a bird attack a butterfly. Upon first reading 

 this statement, while yet in manuscript (parenthetically I may 

 record the pride I now feel that my dear old friend should 

 have asked me to revise these chapters ere yet they had 

 appeared in print) it at once struck me as startling ; yet casting 

 back in mental retrospect, I could then only recall a single 

 exception to the rule stated. During more than a decade which 

 has since elapsed I have paid special attention to the point both 

 at home and abroad, with the result that, while in Northumber- 

 land, I have thrice seen birds attack butterflies, or simulate an 

 attack- no such occurrence has ever come under observation 

 in Africa. Butterflies, in that continent, are practically immune 

 from attack by birds. 



The mantis habitually preys on butterflies, and so do lizards. 

 The former (which is itself admirably assimilated to its 

 environment) succeeds solely by patient statuesque immobility 

 awaiting the arrival of a victim by some attractive bloom : 



