THE GECKO S TOE. 



273 



Under- surface of 

 Gecko's Toe 

 (magnified;. 



facility with which they climb up the vertical plane of walls, and 

 walk in an inverted position on the ceilings of rooms. For this 

 wonderful faculty, which, to all appearance, sets the laws of gra- 

 vitation at defiance, they are indebted to an admirable pneumatic 

 apparatus, which they employ in a manner similar 

 to that of the house-fly. The under-surface of 

 each of the five toes, which, with the exception of 

 the thumb, terminate in a sharp claw, is furnished 

 both in the fore and hind-feet with as many as six- 

 teen transverse folds or plica3, which open into as 

 many cavities or sacks. The contraction of the 

 muscles acting upon these plicae and sacks erects 

 the former, and dilates the cavities of the latter ; 

 the serrated edges being at the same time accu- 

 rately applied to any smooth surface, a vacuum 

 is produced, and by this structure the animal is 

 enabled to perform its wonderful equilibristic 

 feats without fatigue or any extraordinary effort. 



The graceful anolis, which are peculiar to America, are simi- 

 larly provided with suckers and long claws for the purpose of 

 climbing, and moreover their strong muscular hind-legs enable 

 them to leap with singular agility. 



The chameleon is as perfectly fitted for maintaining itself 

 with perfect ease and safety on the agitated branches of trees 

 as the gecko for climbing on sur- 

 faces at every possible angle of 

 inclination ; for its short, strong, and 

 muscular limbs are so constructed 

 that two thumbs opposite to three 

 fingers on the anterior extremity, .chameleon. 



and three thumbs Opposite to two (Chameleo Africanus.) 



fingers on the posterior, form as it were a kind of pincers or 

 hand, admirably suited for a holdfast. This strange animal 

 possesses further a strong flexible and prehensile tail such as 

 has been given to no other reptile, and which of course renders 

 it material assistance in the maintenance of its arboreal station. 

 The skinks, a family of lizard-like reptiles in which 

 there appears to be a gradual transition from the form 

 of the lizards to that of the serpents, have but very short leas - 



