THE BIOLOGY OF THE RED-BACKED SALAMANDER. 347 



above a dish of water that it was constantly wet. No mould 

 appeared, the moisture was constant, and the eggs developed. 



An embryo just out of the egg is 2 cm. long; the gills are present 

 but not quite so large as they are a day or two earlier. The head 

 seems larger compared with the rest of the body, than in the 

 adult stage. There is a large quantity of yolk visible which 

 persists for several days. 



In this cluster of eight eggs, five were allowed to hatch norm- 

 ally, three were opened for pictures. The hatching of the 

 five covered a period of twenty-four hours. The actual process 

 of hatching was not observed. 



There is a small amount of jelly and membrane left; this was 

 noted both in the laboratory and in the field where nests were 

 under observation. Beneath one stone, the pedicel and gela- 

 tinous substance was observed after the eggs had hatched. It 

 had turned dark and was tough and leathery. 



The embryos just out are very active and show several char- 

 acteristics of the species. Salamanders, less than a day old, 

 avoid water, wriggle if annoyed and cling to the surface of the 

 glass jar. 



The gills shrivel rapidly; at the end of twenty-four hours, 

 there are but mere stubs. 



SUMMARY. 



In summing up the results of the observations reported above, 

 the writer makes the following statements: 



1. The red-backed salamander is found throughout all the 

 eastern United States and Canada. 



2. It lives beneath stones and logs, ranging from rather dry 

 to wet places. 



3. It is a small salamander, usually about three and one half 

 inches in length. 



4. It is almost entirely nocturnal. It is quick of motion 

 and a climber; it cannot live in water. 



5. The food consists mostly of live insects, larva?, worms 

 and spiders. 



6. Snakes and frogs are probably its greatest enemies. 



7. The protective devices are autotomy and the secreting 

 of a viscous fluid from the tail. 



