268 AMPHIBIA 



but two young at a birth, and these feed on the other eggs in the 

 uterus and metamorphose before birth. It was claimed by Paul 

 Kammerer that this type transformed to another species on bringing 

 S. atra to the lowlands. 



The spotted or fire salamarjder {Salamandra maculosa) is the 

 European species that Kammerer claimed to have duplicated by 

 placing S. atra in water. S. maculosa is found in moist places, 

 except when it spawns. Then it seeks the water and deposits fifteen 

 or more eggs which have been fertilized by a spermatophore dis- 

 charged into the water by the male. The young take nine or ten 

 months to develop, and live as gilled forms for about four months 

 before they metamorphose into the land type. The cutaneous 

 poison of the fire salamander is a milky white fluid fatal to small 

 mammals and to the cold-blooded animals as well. It is extremely 

 painful when applied to mucous surfaces. 



The tiger salamander {Ambystoma tigrinum) is black with yellow 

 spots which may extend from blotches to broad stripes and bands. 

 It lives on land, but its larval form, once called Axolotl, may remain 

 aquatic or transform according to circumstances and individuals. 

 The capacity to retain the larval body and become sexually mature is 

 called Neoteny and is a most interesting attribute of certain Am- 

 phibia. 



Family 3. Oroteidae. {The Mud-Puppies.) — The common 

 mud-puppy ( Necturus maculatus) of North America is possessed of 

 large fringed external gills. It has small limbs, lidless eyes, and 

 lacks maxillary bones. It is of a brownish color, with black spots. 

 (Figure 143.) 



The blind cave mud puppy {Proteus anguineus) is found in caves 

 of Central Europe. It has a white body, with three pairs of bright 

 red gills. When taken from darkness and exposed for a time to the 

 light the skin becomes patched with gray and finally a jet-black. 

 Typhlomolge rathbuni is a similar form found in the caves of Texas. 



Family 4. Sirenidae. {The Sirens.) — The mud-eel {Siren 

 lacertina) is interesting because of its retrograde metamorphosis. 

 Cope found that its young lose their external gills and then rede- 

 velop them. However, old Sirens can live without gills. 



References on the Urodela 



Bishop, S. C. 1926. Notes on the Habits and Development of the Mud 

 Puppy. N. Y. St. Mus. Bull., no. 268. 



