124. REPTILES OF THE WORLD 



take food from the hand and at length could not be in- 

 duced to spread their capes. If placed on the floor, 

 then suddenly startled, they would, like many species 

 of several famihes, rear upon the hind hmbs and run 

 swiftly in that position. Their color was a dull, slaty 

 gray, often varying according to their mood or changes 

 in the temperature. 



The Spiny-Tailed Lizards, Uromastix: The six 

 species are sometimes called Mastigures. All have a 

 much flattened body covered with granular scales, a 

 small blunt head, tiny bead-like eyes and a thick, curious 

 tail like a spiked war-club. These lizards inhabit the 

 desert regions of southwestern Asia and northern 

 Africa. Uromastix spinipes is the largest species, liv- 

 ing in portions of the Sahara Desert. The spines on 

 the tail are arranged in regular rings and so sharp are 

 the protuberances the organ serves as a formidable 

 weapon. The hue of the body is uniform dull brown 

 or yellowish, to match the sterile soil on which the crea- 

 ture lives. So tiny are the eyes thej^ might seem to 

 us to furnish inadequate powers of vision; but appear- 

 ances are deceiving. The JMastigure has keen sight and 

 makes ofl^ at a lumbering gait at the approach of an 

 intruder. If it reaches its burrow, or crevices among 

 rocks, instant advantage is taken of the shelter; how- 

 ever, the reptile's progress is rather clumsy and a man 

 can easily overtake it. Then it vigorously prepares to 

 defend itself, slashing the formidable tail from side to 

 side or rearing upward in an eff'ort to bite. As the jaw 

 bones are practically bare — within the mouth — and come 

 to a sharp edge, besides provided with thickly-set, 

 curiousty-flattened teeth, an adult example can bite 

 deeply, then aid the effort by a quick rotary twist of 

 the body, producing anything but a superficial lacera- 



