38 BERTRAM G. SMITH. 



V. Post-larval Development. 



A series of sizes intermediate between the 12 cm. larvae and 

 the adults was obtained. Six specimens taken during a single 

 week in August measured as follows: 14 cm., 16.2 cm., 18.3 

 cm., 21 cm., 21.5 cm., 26.7 cm. All these had lost their 

 external gills, but were sexually immature. The lateral folds 

 show increased development throughout the series. The colora- 

 tion is about the same as that of the young adult ; Fig. 14 will 

 serve to show the general appearance of the specimens ranging 

 from 16 to 35 cm., in which the spots are more conspicuous than 

 in either very young or very old specimens. 



Sexual maturity is attained with a length of about 34 cm., and 

 probably requires three or four years from the time of the fertiliza- 

 tion of the egg. 



In conclusion, I take pleasure in acknowledging my indebted- 

 ness to Professor Jacob Reighard for training in field work with- 

 out which it would have been impossible for me to conduct studies 

 of this kind far from the advantages of a laboratory, and to Dr. 

 O. C. Glaser, under whose direction work was continued at the 

 university, for invaluable encouragement and advice. 



University of Michigan Zoological Laboratory, 

 Ann Arbor, Michigan. 



literature cited. 



Assheton, Richard. 



'96 Notes on the Ciliation of the Ectoderm of the Amphibian Embryo. Quart. 

 Journ. Micros. Sc. , Vol. 38, p. 465. 

 Gadow, Hans. 



'01 Amphibia and Reptiles. Vol. VIII. of Cambridge Natural History. 

 Gage, Simon Henry. 



'gi Life-History of the Vermilion- Spotted Newt (Diemyctylus viridescens Raf.). 

 Amer. Nat., Dec, 1891. 



Hay, 0. P. 



'88 Observations on Amphiuma and Its Young. Amer. Nat., Vol. XXII., No. 

 257. 

 Ishikawa, C. 



'04 Beitrage zur Kentniss des Riesen- Salamanders ( Megalobatrachus maximus 

 Schlegel). Proc. Dept. Nat. Hist., Tokyo Imp. Mus., Vol. 1, No. 2. 

 Jordan, Edwin 0. 



'91 The Spermatophores of Diemyctylus. Journ. Morphol., Vol. V., No. 2. 



'93 The Habits and Development of the Newt (Diemyctylus viridescens). Journ. 

 Morphol., Vol. 8, No. 2. 



