GROWTH AND AGE AT MATUBITY OF THE PACIFIC RAZOR CLAM 
211 
in 10 days during this period of low temperature than during the 2 days of the 
preceding year. From all indications spawning may have been suspended entirely 
during part of the time. No attempt was made to correlate the rate of spawning 
with the number of larvae in the water, which Nelson has shown to be possible Avith 
the oyster. The condition of the clams was determined by opening a large number 
and making direct observations on the contents of the gonads. 
Temperatures taken in Alaska near the spawning time were very similar to 
those on the Washington beds. The open beach near Cordova had a temperature 
of 13.9° C. on July 16, which was shortly after the onset of spawning. The pro- 
tected waters of Orca Inlet and adjoining bays from which claims weie taken 
varied in temperature from 12.8 to 14.5° C. The temperature records from 
Swickshak Beach showed an average of 13.5° C. at spawning time. 
These figures suggest a critical temperature of about 13° C. (55.5° F.) 
for the razor clam, as compared with 21.0° C. (70° F.) for the oyster. The 
summer temperature of the Alaskan waters is quite high in all cases, except where 
influenced by glaciers or glacier-fed rivers. The variation from day to day in 
the Ketchikan records is less striking than on the Wasliington coast. For 
instance, the variation at Ketchikan for the month of July was from 13.5 to 
16.0° C, and for August, 13.0 to 17.0° C. In contrast to this, similar figures for 
the Washington coast were as follows: July, 10.6 to 17.2° C. ; August, 11.1 to 
17.2° C. On two occasions during the summer of 1923 tlie temperature of tlie 
shore water at Copalis dropped more than 6° (centigrade) over night. Tliis 
cold water was accompanied by a fog which was largely confined to the beach. 
Crab fishermen outside the harbor declared it was clear a shoit distance offsliore, 
and personal observation showed the fog to extend not more than half a mile inland. 
A few hours after the cold water was noticeable on the beach a peculiar 
collection of material was cast up by tlie surf. It contained a great many sponges, 
snails and snail shells, worm tubes, cast crab shells of several varieties, and a great 
mass of other detritus, which ordinarily rest lightly on the bottom. This indi- 
cated the presence of a current of comparatively high velocity moving landward 
over the bottom, which caused an upwelling of cold water along the shore. It was 
evidently of small extent, as it affected not over 20 miles of coast line. 
It was suggested by McEwen, in a personal communication, that this up- 
welling was not similar to one described b}' him (McEwen, 1912) from the Cali- 
fornia coast but, rather, it was caused by some local condition of the air currents. 
While the Ketchikan temperature record does not show the sharp transient drops 
that might be expected from such an upwelling, this would not prove that up- 
wellings do^ not occur in this region. Their effect would be most marked on the 
outer coast; as, for example, on the west side of Prince of Wales Island the 
circulation of the tide among the many islands of the Alexander Archipelago 
would tend to obscure fluctuations of the inland waters about Ketchikan. 
As has been shown by J, Nelson (1917), oysters acclimated by living for 
many years in the Gulf of St. Lawrence have a rediiced critical temperature of 
20° C. (68° F.). It has been further shown by T. C. Nelson (1921) that oysters 
moved from New England to New Jersej' spawn two weeks earlier than do the 
