50 COPE1A 



Unfertilized ova, indicated by white, opaque eggs, 

 amount to about 20%. While actual observations 

 concerning the date of ovulation were not obtained, 

 it seems safe to assume that this could not have taken 

 place until the ponds were at least partially free from 

 ice, which would fix the date not earlier than April 

 1st. Some of the egg-masses, judging from the ad- 

 vanced state of disintegration of the unfertilized ova, 

 probably were deposited about that date, others, esti- 

 mated on the same basis, were not over 2 or 3 days 

 old. Workmen on the Hudson Estate had not come 

 across any of the adult salamanders so far during the 

 present season. 



April 10th. — The ova of two out of four egg- 

 masses kept in an aquarium at the laboratory have 

 changed in form from spherical to arcuate, causing a 

 proportionate enlargement of the clear cell surround- 

 ing them. The ova in the other two egg-masses are 

 still spherical though somewhat enlarged. 



April 18th. — Two larvae have hatched and are 

 actively swimming about. Total length, 13 mm. 

 Head very large, flattened. Eyes prominent, pupil 

 black, iris speckled golden yellow. Gills and caudal 

 membrane well developed. Yolk sack almost ab- 

 sorbed. Limbs not visible. Color, dorsally olive grey, 

 speckled and irregularly blotched ; ventrally pale buff. 

 Magnification shows asteroid arrangement of pigment 

 cells embedded in skin. Caudal membrane, extending 

 dorsally to gill slits and ventrally to vent, is translu- 

 cent, showing very faint pigmentation. 



Developing embryos frequently turn or wriggle 

 within the clear cells which attain a maximum diam- 

 eter of 10 mm. and are filled with "watery fluid." 



April 22d. — Twelve larvae have hatched. They 

 are feeding on the very young nymphs of mayflies 

 and dragonflies, introduced with aquatic plants. 



