AMPHIBIA 19] 



poison is due to a cutaneous secretion. The breeding habits are 

 rather odd. In July after a preliminary exciting- performance between 

 the sexes on land, both males and females go into the water, but leave 

 the heads out. The male deposits a spermatophore, or package of 

 sperm, which the female partly takes into the cloaca. Fertilization 

 is internal and slow development occurs in the uterus, taking about 

 ten months to complete itself. The well-developed young, to the 

 number of about fifteen or so, are born in the water. The species is 

 therefore truly viviparous. The larvae have external gills and live in 

 the water for about four months and then very slowly metamorphose 

 into the terrestrial adult form. 



Salamandra atra is an alpine form like S. maculosa but much darker. 

 It occurs in mountain lakes at an altitude of 2,000 to 9,000 feet above 

 sea level. It produces only two young at a birth. These, while still 

 in the uterus, feed upon the other eggs found there and metamorphose 

 completely before birth. Kammerer claims that S. atra can be 

 changed into S. maculosa by bringing them into the lowland waters 

 and that after they have been kept there for a few generations they 

 tend to retain the breeding habits of the lowland form though trans- 

 ferred back to the Alpine environment. This has often been cited 

 as evidence in favor of the inheritance of acquired characters, a doc- 

 trine which is quite generally unacceptable to biologists, but is 

 strongly advocated by a small but growing minority. 



Diemictylus viridescens is a good example of the "efts," sometimes 

 also called "newts." It is commonly called the "vermilion spotted 

 eft." It has a prolonged life history, taking several years to reach 

 full maturity. For the first three years it lives in the water, being 

 green in color and having external gills. It then leaves the water and 

 becomes yellow with vermilion spots. After some time it again re- 

 turns to the water, becomes green, and lives an aquatic life during the 

 breeding season, after which it once more takes on the terrestrial 

 features and migrates to land. The life cycle of this species illustrates 

 as well as any other the extreme plasticity of the group and the deli- 

 cate equilibrium that exists between the aquatic and terrestrial 

 phases. 



Triton cristatus (Fig. 112, C and D), the "crested newt," received its 

 name from the fact that in the male (Fig. 112, D) there is a pronounced 

 dorsal crest during the breeding or nuptial season. The color at this 

 time is also very striking, the top of head being marbled black and 



