MOVEMENTS OF LIZARDS 51 



very numerous ribs. When the snake desires to move, 

 the ribs are raised one after another by the lateral 

 body-muscles, and the scales, pressing against the 

 ground, serve to propel the body forward. At the 

 same time, owing to the singular flexibility of the back- 

 bone, the lateral, eel-like movements bring the lithe 

 body over the ground with great rapidity. 



Although the reptiles of to-day are inferior to 

 those of the past, which walked erect, ran doglike or 

 flew, there is at least one group among them — that of 

 lizards — which is at its prime, and amongst these one 

 or two may be specially mentioned. 



In zoological gardens geckos may sometimes be 

 seen. They are small, extremely active when roused, 

 and provided with padded adhesive fingers and toes. 

 By the aid of these pads geckos are able to perform 

 the strangest feats. When hunting for flies they run 

 up and down papered walls, and even glass windows. 

 So sure is their hold that they can run up a wall, bend 

 over, and slide along the ceiling. Like other lizards, 

 geckos often lie motionless for a long time, but evade 

 capture not by a run that can be seen but in a flash of 

 gliding. Such geckos are household pets in the East. 

 But perhaps the most agile of all is a lizard found in 

 Malay, which is so active as to run securely over the 

 tops of grass shoots. 



In mammals the organs of movement are far more 

 effective. The tail is reduced and the longitudinal 

 muscles of the back — heirlooms from fishes — are 

 employed for the work of the shoulder and hip. The 



