Description.—General colour greyish, with a number of lozenge-shaped black markings, edged with yellowish white upon the back; the tip of the tail black; the belly yellowish white; at the extreme end of the tai] a number of horny rings, or rattles, increasing in number, as is supposed, with the age of the reptile.

Length.—They are frequently found over six feet in length.

LUCKY is it for the backwoods' hunter that there are but few species of this venomous genus, and that they are all provided with the rattles, from which they take their name, and with which they give a timely warning to the intruder who may venture too near their haunts. The poison of the rattlesnake is extremely virulent; more so in the hot parts of America than naturalists, who have only seen the reptile in this cold land, can at all realise.

This warning sound has saved many lives; and statistics will go far to prove that, in spite of all our prejudice against the serpent tribe, the number of human beings actually injured by them is very small. The rattlesnake, like most venomous reptiles, seldom makes an unprovoked attack upon man.

The structure of the rattle found on this class of reptiles is very curious. It has been supposed to consist of a number of bones loosely contained in a horny case, the agitation of which produces the noise.