GECKOS, LIZARDS, AND CHAMELEONS. 87 



on the skin of species that frequent arid, sandy 

 localities. In the " Horned Toad " (Phrynosoma), 

 for example, of the western half of the United 

 States and Central America, the horny scales 

 have become transformed into a bristling armour 

 of sharp-pointed spines of varying size. The 

 larger of these spines closely resemble the dried 

 husks of seeds and thus afford protection to the 

 animal by causing it to harmonise with its sur- 

 roundings. These rather forbidding looking 

 creatures are fond of basking in the broiling 

 sun, and in the afternoon, when the sand is 

 heated to fever heat, they begin to retire for 

 the night. This they do within a very short 

 space of time, by moving the body slowly for- 

 wards in such a way that certain peculiar scales 

 arranged like a fringe along the sides of the 

 body turn the sand up over the back after the 

 fashion of a plough. Soon only the head remains 

 visible, and this looks like a little cluster of dry 

 thorns. To prevent the sand getting into the 

 nostrils the latter are provided with special 

 closing valves. About a dozen species of horned 

 toads are known, the largest of which is about 

 eight inches in length. 



Strangely enough, another spine-covered lizard 

 occurs in Australia, and is known as the Moloch 

 Lizard (Moloch horridus). But little appears to 

 be known about this animal save that it feeds 

 upon ants. The spines embossing the skin appear 

 to be extremely hygroscopic. This fact was dis- 

 covered by Dr Willes who, placing a live speci- 

 men in a shallow dish of water, remarked that 

 the water was immediately sucked up as by 



