34 
FIRST BOOK. 
creatures the scales are like strong, horny plates, 
and so hard that often a bullet will bound off 
from them instead of piercing a hole." 
" When you touch a lizard it doesn't feel very 
warm, as a cat or a bird does," said Nell. 
6. " That is because its blood is not warm, like 
theirs is," said Will. Teacher says that a rep- 
Hing- tailed Iguana— one of the Lizard family. 
tile is a cold-blooded animal. The warm-blooded 
animals mostly have hairs or feathers to keep in 
the warmth. 
7. ''Let tlie lizard run. There, Nell: do you 
know why it can twist and bend its body, to turn 
from side to side? It is because its long back- 
bone has so many joints in it." 
''What pretty feet it has!" said Nell, as she 
looked at the neat little toes spread out on the 
ground. 
