He has a flatter back than the Frog, the bones of the pelvis not producing so sharp an angle; and the hind legs are not so long in proportion to the body, only slightly exceeding the length of head and body, whereas in the Frog they are one and a half times that length. The Toad seems more solidly built than the Frog, with broader head, shorter limbs, and in general aspect is closer to the earth, a heavier, more grovelling creature than the vaulting Frog. This earthliness is accentuated by the texture and colour of his skin. Instead of the moist and shining, bright coloured coat of the Frog we have a dry, dull, pimply skin so strongly resembling the earth that he is frequently passed by as a lifeless clod. That is one of the Toad's strong points; and he has the patience to squat motionless for hours, tiring out any enemy that looks for movement as proof of life. He is too heavy to take a leap; instead he progresses by very short jumps on all four feet which give the impression of being accomplished only by a great effort. But he rises alertly to his full quadrupedal height when he is considering the best way to negotiate a worm. The colour of the Toad varies a good deal according to the nature of the soil upon which he happens to live. It is usually some tint of brown or grey, but the brown may be almost red in sandpits, a rich brown or a dirty brown; the grey may be light or with an olive tinge or a sooty hue that may pass as black. As he is only active in the evenings and at night, any of these tints serve to render him inconspicuous in the general duskiness. Even his bright eyes, being coppery-red in colour, do not serve to draw attention to him. [Illustration: _Pl. 104._ _M 166._ *Natterjack Toad.* Bufo calamita.] [Illustration: _Pl. 105._ _M 167._ *Natterjack and Common Toad*, showing principal differences in the two species.] The pimples of various size that diversify his skin are not mere ornament, though they help materially to produce the clod-resemblance. They are glands that on occasion pour out an acrid and offensive fluid that often saves the Toad when he is caught up in the jaws of some unsophisticated carnivorous beast or bird. Experience teaches such enemies to leave the Toad alone. The largest of these glands--the parotid--may be seen as an elongated, porous swelling behind the eye. The underside is whitish, the white being qualified always with an admixture of yellow, brown, or red, sometimes spotted with black.