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University of California Publications in Zoology [Vol. 27 
As development proceeds, the jelly swells to larger size than the 
dimensions given above so that when the embryos are ready to hatch 
the outer jelly coat is almost twice its original diameter. On the 
morning of April 11, at 11 a.m., the water immediately about the egg 
masses was at a temperature of 21.0° C. This relatively high tempera- 
ture is most certainly a factor in the rapid development of the eggs, 
but it probably is also dangerous in some degree in that it permits 
also the rapid development of a fungus which may gain entrance to 
the vitelline capsules. It was noticed that in masses of eggs advanced 
in development fully 50 per cent of the eggs had failed to develop 
or had developed only to a relatively early stage. 
The seasonal program of Soaphiopus hammondii in California is 
indicated by the items in the following table. Except as noted, this 
table is based on material in the collection of the Museum of Verte- 
brate Zoology. 
Locality 
Date 
Stage of development 
Bellota, San Joaquin Co 
March 11, 1923.. 
Small larvae 
Santa Maria, Santa Barbara Co 
Apr. 10-11, 1923. 
Eggs in early stages and 
others ready to hatch 
Jenny Lind, Calaveras Co 
Apr. 9, 1922. ... 
Large larvae, with hind 
limbs 
Grounds of Southern Branch, Univer- 
sity of California, Los Angeles 
Apr. — , 1921 
Larvae with hind limb 
buds 
Arroyo Seco, Los Angeles 
May 3, 1921 
Metamorphosing larva 
Bellota, San Joaquin Co 
May 8, 1923 
Large larvae* 
Sierra Madre, Los Angeles Co 
May 11, 1913 
Large larvae, some meta- 
morphosingf 
Sierra Madre, Los Angeles Co 
May — , 1914 
Large larvae, some meta- 
morphosingf 
2 mi. w. Sierra Madre, Los Angeles Co. 
Carrizo Plain, 7 mi. se. Simmler, San 
May 20, 1913 
Many larvae, some with 
hind limb buds just ap- 
pearing, others with tail 
practically resorbed 
Luis Obispo Co 
3 mi. e. Whitmore Tub, Long Valley, 
May 28, 1911 
Two young with tail stub 
less than half length of 
body 
Mono Co., altitude, 6800 feet 
July 12-13, 1922. 
Large larvae, some toads 
completely metamorph- 
osed 
* H. J. Snook, in letter; these larvae transformed in the laboratory prior to May 18. 
t C. L. Camp, MS. 
