342 



GENERAL ZOOLOGY 



the hand of an axolotl ten years old was removed, and it 

 was replaced within twelve weeks. Often more than the 

 usual number of digits is replaced ; this tendency is greatest 

 in those cases where the limb is cut off close to the body. 



The Alpine salamander (Salaman'dra a'tra), found in moist 

 places two thousand feet in altitude, especially near water- 

 falls, in the Alps of Europe, is remarkable for its breeding- 

 habits. Only two young are produced at a time, and these 

 are born alive at an advanced stage of development. During 



FIG. 170. Development of Newt. Reduced. (After Gage) 



A, Egg on water-plant; Ji, larva (in August); C, young, in autumn; D, about 

 two years old ; E, adult 



the time they are within the mother's body they are nour- 

 ished by the nutritive matter from several eggs, which only 

 partially develop. 



The newts, or tritons, are carnivorous salamanders which 

 are more or less aquatic in their habits when adult, or, at 

 least, during the breeding-season, at which time also the colors 

 of the males in some species become brighter, and a crest is 

 developed along the back. The common species of the eastern 

 United States (Diemy c' tylus virides' cens, Fig. 170) is olive- 

 green or reddish in color, with a compressed tail and a row of 

 small orange-colored spots along the right and left sides of 

 the body. It grows to the length of three and a half inches. 

 The eggs (Fig. 170, A) are laid during April, May, or June, 

 usually in the axils of leaves of water-plants, and the leaves 

 are drawn together and made into a compact mass by a 



