_The inflation of the body, and other means of exciting fear in an enemy_.—Certain Amphibians and Reptiles, which either have no spines to erect, or no muscles by which they can be erected, enlarge themselves when alarmed or angry by inhaling air. This is well known to be the case with toads and frogs. The latter animal is made, in AEsop’s fable of the ‘Ox and the Frog,’ to blow itself up from vanity and envy until it burst. This action must have been observed during the most ancient times, as, according to Mr. Hensleigh Wedgwood,[421] the word _toad_ expresses in all the languages of Europe the habit of swelling. It has been observed with some of the exotic species in the Zoological Gardens; and Dr. Günther believes that it is general throughout the group. Judging from analogy, the primary purpose probably was to make the body appear as large and frightful as possible to an enemy; but another, and perhaps more important secondary advantage is thus gained. When frogs are seized by snakes, which are their chief enemies, they enlarge themselves wonderfully; so that if the snake be of small size, as Dr. Günther informs me, it cannot swallow the frog, which thus escapes being devoured. Chameleons and some other lizards inflate themselves when angry. Thus a species inhabiting Oregon, the _Tapaya Douglasii_, is slow in its movements and does not bite, but has a ferocious aspect; “when irritated it springs in a most threatening manner at anything pointed at it, at the same time opening its mouth wide and hissing audibly, after which it inflates its body, and shows other marks of anger.”[422]