ANGLES IN WATER. 
223 
spontaneously, but in order to try tlieir natatory 
powers, I caught a male Purple-tail, and placed it in 
the midst of a deep pool of clear water. It floated 
like a cork, as might have been expected from the 
volume of the lung, and from its capability of infla- 
tion. It was not more than half immersed, and as 
the whole skin repelled water, the fluid stood around 
it, in the form of a little heap or bank. The animal 
struck out vigorously for a few seconds, moving the 
feet alternately, the right fore with the left hind 
foot, and vice versa, as in running ; and this motion 
threw the body into lateral serpentine undulations. 
It made way thus, but soon relaxed, and then inter- 
mitted its exertions, and floated motionless. On my 
taking it up, I found it much exhausted ; and 
though, on being again put in, it struck out anew, 
yet it was each time more languidly, until I Anally 
rescued, it, and restored it to dry land, where, though 
it lay helpless and almost motionless awhile, it soon 
recovered its agility in the warm sunshine. From 
this experiment I judge that this species could not 
swim the distance of a yard before it would become 
exhausted, and drown. 
The Anoles, and I believe all the quadruped 
Saurians, progress only by the alternate use of the 
right and left feet ; never galloping, how swiftly 
soever they may move. In rapid running, they 
commonly elevate the tail above the general line of 
the body. Perhaps this is what Lacepede means 
when he says of Anolis hullaris, that it carries the 
tail habitually raised above the back. 
The green hue of the Purple-tail when enjoying 
