IOS URODELA 



CHAP. 



the table, the creature will frequently execute a well co-ordinated 

 spring and alight on its feet some distance away, instead of 

 falling over the edge in the typical salamander -fashion. This 

 species is nocturnal and entirely terrestrial, and seems to be 

 indifferent even to proximity to water. Rotten stumps and logs 

 are the habitations preferred, and wherever these occur in the 

 region about San Francisco Bay, even though at the places 

 remotest from water, specimens are sure to be found. 



The eggs are laid in a hollow under ground, and the female 

 seems to remain curled around them until they are hatched, 

 which takes place in two or three weeks. The specimen observed 

 by Eitter and Miller laid 19 eggs. Each was contained in 

 a gelatinous capsule 6 mm. in diameter, and was firmly anchored 

 to a clump of earth by a narrow peduncle about 8 mm. long. 

 The embryos developed very large gills, each being composed of 

 three broad membranous lobes, the latter being thin and delicate, 

 much expanded, highly vascular and widely confluent at their 

 bases, so that the gills of each side really form one three-lobed 

 mass. Their dorsal surfaces are applied to the inner surface of 

 the egg-capsule. The amount of food-yolk is considerable. The 

 whole larval life is passed through within the egg. Before the 

 young is hatched the gills wither and cease to be functional, and 

 the gill-slits close up. The tail is round, and shows no indica- 

 tion of a fin at any time during the larval period. Xewly hatched 

 individuals appeared much distressed when put into water, and 

 were quite unable to swim. They immediately sank to the 

 bottom and remained there until they were removed. The 

 integumentary sense-organs, so well developed in the aquatic 

 larvae of Urodeles, are entirely wanting. When hatched the 

 young creature is about 32 mm. long ; its general colour is 

 blackish-grey, finely sprinkled with bluish-silver. During the 

 second year this garb is changed to the dusky brown of the 

 adult, and the fine silver speckling is replaced by much larger 

 and less numerous yellow spots. 



Although one of the most terrestrial of Urodeles, this species 

 is lungless, but the skin remains delicately smooth and moist 

 throughout life. According to the observers quoted, the pharynx 

 plays an important part in respiration. From 120 to 180 or 

 even more vibrations are made by the throat in a minute, and 

 in some cases these movements are grouped into series of about 



