[[p. 1]] Mr. A. R. Wallace, F.Z.S., read the following extracts from letters of Mr. John Wallace:--

"Stockton, California, May 1870.

    "There is common on dry sandy plains a small animal known [[p. 2]] here as the 'Horned Toad,' but which is a Lizard (Phrynosoma, sp. ?), having a broad body and short tail, covered all over with horny protuberances, and on the head five or six short and stout horns arranged like a crown. Under certain circumstances, apparently as a means of defence, this creature squirts out from one of its eyes a jet of bright-red liquid very much like blood. This I have observed three times from three different individuals, although I have caught many that did not do it. They do not generally use this defence when first captured, although I caught one a few days ago which squirted the liquid a distance of six inches over the back of my hand, and another ejected it when I flourished a bright knife before its eyes."

"October 1870.

    "I have not got hold of a Phrynosoma lately, though they are common both in the mountains and the plains. It is only rarely that you can observe the squirting of the red liquid from the eye, as I have frequently tried to produce it and failed. I think it must come from the eye, as there appears to be no other place where it could come from."

    "With regard to Rattlesnakes, I have caught and killed dozens of them when I was in the mountains. When first seen or disturbed they are generally coiled up, with the tail erected in the centre of the coil, vibrating rapidly, so that it scarcely appears to move at all, the head slightly erected towards the point of danger. If not immediately attacked they will work themselves backwards, without altering the relative position of the head and tail, still rattling. The sound, as near as I can recollect, is more like the singing of a cricket in the fields than any thing else--perhaps not so high a pitch, and a little more tremulous."

    Mr. A. R. Wallace stated that a lady who had resided in the southern states of North America had also compared the sound of the rattle when heard in the woods to the chirping of an insect; and if this was the case, and the animal made the noise when coiled up and before being disturbed, it would go far to explain the use of the rattle, which would be simply a decoy to insectivorous animals, to enable the sluggish serpent to capture them.