266 NEW YORK STATE MUSEUM 



may be seen from the following data taken from the Field Note 

 Book of Fishes, Amphibians, Reptiles and Mammals by A. H. Wright 

 and A. A. Allen: 



Spotted salamander, Ambystoma maculatum (Shaw) Egg-trans- 

 formation 4-6 months 

 Red-backed salamander, Plethodon cinereus (Green) 2.5-3 months 

 Purple salamander, Grinophilus porphyriticus (Green) Possibly 



2 or more years 

 Two-lined salamander, Eurycea bislineata (Green) Possibly 2 years 

 Newt, Notophthalmus viridescens (Raf) 4-8 months 



In the case of D. fuscus, Wilder estimated the probable 

 duration of incubation alone to be 5 weeks, and the aquatic larval 

 period, during which the gills are retained, to extend over an addi- 

 tional period of 9 to 10 months. 



The chief points of interest in the life history of the four- toed 

 salamander may perhaps be profitably summarized : Adults of both 

 sexes are strictly terrestrial during the greater part of the year. 

 In the latitude of central New York release from hibernation occurs 

 in April and it is probable that pairing of the sexes takes place soon 

 after. During the latter part of April or early May the female, 

 at least, migrates to situations suitable for ovulation and after 

 depositing the eggs remains with them. The period of incubation 

 is variable depending on conditions but doubtless limited to 30 or 

 40 days. From the scant evidence of observations on a single indi- 

 vidual it may be that transformation is accomplished in an additional 

 period of 10 to 20 days. The adult size is probably not reached 

 until the end of the year following that of transformation. Migra- 

 tion to terrestrial situations from the bogs must occur in summer 

 or early fall. 



The large number of eggs deposited, their intimate relation to 

 sources of moisture and early absorption of the yolk, indicate recent 

 adaptation to terrestrial life. 



A ckn owledgments 



I am particularly indebted to Dr A. H. Wright of the department 

 of zoology, Cornell University, for kindly interest and suggestions, 

 many notes and personal observations on the four-toed salamander 

 and -for identification of plants in the field; to Prof. C. R. Crosby 

 of Cornell for photographs here reproduced, all of which were taken 

 under adverse conditions; and to Miss Julia Moesel, who kindly 

 loaned me her account of the species, containing many records and 

 observations. 



