166 FIRST BOOK OF ZOOLOGY. 



while the salamander now being described has none. On 

 touching the cat it feels warm, while the salamander feels 

 cold to the touch ; with the cat the young are born alive, and 

 the little kittens have the same general features as the parent- 

 cat. The salamander lays a number of eggs, and most of the 

 species lay their eggs in the water ; when these hatch, the 

 creatures coming from them have no lungs and cannot 

 breathe air directly, but have gills instead. More curious 

 still is the fact that, when the young creature hatches from 

 the egg, it has no legs, these appearing afterward as the ani- 

 mal grows. 



The following figure represents the appearance of a young 

 salamander ten days after hatching from the egg. The gills, 

 appearing like feathers, are seen on the sides of the neck. 



g 



FIG. 149 YOTTNG SALAMANDER. g, </, Gills.- (After a figure by Dr. P. E. Hoy.) 



149. Thus, while there are important differences between 

 the cat and the salamander, there are also many points of re- 

 semblance ; and, if the arrangement of bones constituting the 

 skeleton be examined, a still closer resemblance may be seen. 

 Within the body the salamander has a series of bones which 

 together form the skeleton. The most important part of the 

 skeleton consists of a row of bones which runs along the cen- 

 tral line of the back of the body from the head to the tip of 



