ANGLES IN WATEE. 223 



spontaneously, but in order to try their 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 finally 

 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 bullaris, that it carries the 

 tail habitually raised above the back. 



The green hue of the Purple-tail when enjoying 



