Page:The Zoologist, 4th series, vol 3 (1899).djvu/483

Rh black Ants, such as Formica gagates and Componotus æthiops. Prof. Emery suggests that, their numbers being small and their sight not very good, they find it convenient to accompany other Ants which live in larger communities, and they perhaps escape detection from the similarity of colour."

Mr. Skuse considers that the Australian Hepialid moth (Leto stacyi, Scott) resembles in situ an approach to the head of a reptile of the genus Varanus. "The moth is one which passes its larval state in the butts of Eucalyptus trees for the period of five or six years, but on emergence the perfect insect is not prone to fly, and would therefore be very liable to be attacked by birds. Hence the probability that my surmise of the striking resemblance to the head of a Lizard being an instance of genuine protective imitation is correct." Of the larvæ of the Hawk-Moth (Chœrocampa porcellus), it has been stated that should it "be discovered among the dead leaves, where it usually lies concealed, the first four segments are suddenly retracted, and, as in the case of C. celerio, the animal appears to have a very large head, with two glaring and dangerous-looking eyes. This transformation is no doubt of use for defensive purposes." A similar observation is made on the larva of C. elpenor. "In this position its appearance is very striking, and gives a formidable look to the creature in the eyes of those animals that might have been thinking to prey upon it." Poulton has proposed that these caterpillars "terrify their enemies by the suggestion of a Cobra-like serpent"; an hypothesis not so improbable as would appear if C. elpenor is considered a purely European species, whereas it is distributed over "Europe, Japan, Sind, Himalayas, Shillong, Nagas, Manipur"; and thus is found in the area inhabited by the Cobra. Dr. Gregory, in East Central Africa, relates having been "startled by a hissing noise like that of a Snake coming from a clump of grass." On closer inspection he "could just detect a small green head among the stalks, and behind this appeared, whenever the noise was repeated, an expansion like