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University of California Publications in Zoology [Vol. 27 
for some time after the eggs are laid, as some eggs which were laid in 
a glass jar on the night of April 15-16, and which were separate when 
turned into a pan of water the next morning, immediately became 
affixed to the bottom of the pan. 
Some of the eggs found in the stream on the morning of April 15 
were in the four-cell stage and hence had been laid during the preced- 
ing night. Only two or three tadpoles of Hyla arenicolor were seen 
where the egg masses were collected. None of the adult hylas were 
found in the water of the stream during the day save when frightened 
there by the movements of the observer. They were all, as is their 
custom at other times of the year, on the sides of the granite rocks 
bordering or in the stream (Atsatt, in letter). 
The jelly coat surrounding the egg of Hyla arenicolor is colorless 
when the egg is laid and would doubtless continue so if it did not 
gather a coating of fine sediment and debris from the water. So far 
as I can determine there is but one coat of jelly. Typically, this is 
perfectly spherical. 
A number of the eggs laid in captivity on the night of April 15-16, 
1923, by adults taken from Snow Creek, were preserved in 5 per cent 
formalin on the following morning. These now present the following 
measurements, in millimeters : 
Egg 
Jelly coat 
Minimum 
1.83 
4.14 
Maximum 
2.10 
4.68 
Average of 15 
1.95 
4.39 
The vitelline space surrounding the egg measures about 0.1 milli- 
meter more than the egg itself (fig. Z). Discoloration of the surface 
of the jelly coat made it impracticable to measure accurately the 
vitelline capsule in most of the eggs at hand. 
Another smaller series of eggs, some of which were spawned while 
the animals were en route by express from Los Angeles to Berkeley, 
and which were infertile, gave the following measurements, in milli- 
meters : 
Egg 
Jelly coat 
Minimum 
1.88 
3.87 
Maximum 
2.42 
5.00 
Average of 5 
2.19 
4.41 
