1900.] INSECTS OF THE " SKEAT EXPEDITION." 853 



colour and form. Among these leaves, the head and wings, though 

 they are inconspicuous, are not invisible ; the wings may be detected 

 because they are transparent and glary, the head because it is held 

 well raised above the surface on which the insect is sitting. Seen in 

 such surroundings, there is nothing that would lead a human being 

 to judge that the Mantis was a predaceous animal. Indeed, it bears 

 a general likeness to a moth or a non-predaceous JVeuropteron, 

 not particular enough, perhaps, to justify one in saying that it 

 "mimics" any other form, but sufficiently marked to deceive one as 

 to its real nature. The fact that a specimen of the Mantis was found 

 concealed in a dead tree would lend colour to the idea that it is 

 nocturnal, as a large proportion of the Mantidae appear to be. But 

 it is quite possible that it may be sufficiently active in the daytime 

 to seize any prey which comes within its reach. If so, it affords 

 an instance that may be compared with that of the Kanchong. 

 While the latter simulates a flower, and so actually allures its prey, 

 the former sits still and looks harmless, so that its prey chances to 

 come to it uninvited. The difference seems to me to be one of degree. 

 Supposing that a green Mantis were seated among leaves of the 

 same colour as its own body, and that a phytophagous insect 

 alighted upon it, it might then be said to be an instance of 

 " alluring " coloration. Whereas if the insect only alighted near 

 it, the Mantis would scarcely come under this category. In any 

 case the adaptation appears to be calculated to deceive Arthropod 

 prey rather than mammalian enemies. The Mantidse are well 

 adapted for self-defence, and the movements of the Kanchong, at 

 any rate, betray the insect to vertebrate eyes. 



The curious prolongation of the head in Ceratomantis is not a 

 feature of any systematic value ; many other Mantids, belonging 

 to widely separate genera, have a similar peculiarity. Undoubtedly, 

 however, in this case it aids in masking the characteristic shape of 

 the Mantid head ; or, at any rate, appears to do so. 



With regard to the marking on the femora of the fore limbs, 

 similar markings, often emphasized by yellow lines running 

 parallel to them or across them, occur in the same position in 

 a large number of Mantidse. I do not know that a function has ever 

 been assigned to marks situated in this position except by the 

 Russian naturalist Porschinsky, whose interesting observations ', 

 and imaginative explanations thereof, Professor Poulton has been 

 kind enough to have translated for me from the Russian. 

 Porschinsky has a theory that all eye-like markings on insects 

 represent glands, which may be imagined to excrete a noxious 

 fluid. He supposes that such markings simulate the liquid which 

 has issued forth, with the blue sky or some other object reflected 

 in it. He points out that the display of sueh spots is sometimes 

 accompanied by a sound which might be taken to imitate liquid 

 hissing out of a narrow opening such as the duct of a gland. Mantis 

 relvjiosa is one of his examples. He says that there is a large 



1 Lcpklopteronuii Rus.Hirc Blologia, iv. (Petertsburg, 1893), |>. •"•<*>, fig. 10. 



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