638 
CHANNELLED WHELK SPAWNING. 
Rear view of the shell. 
Photo by L. B. Spencer. 
pletion. Although the animal has been under 
almost constant observation in the New York 
Aquarium for a dozen years, the spawning 
process has never taken place there until re- 
cently. 
On the morning of October 4, 1909, a whelk 
with six of the connected egg-cases protruding, 
was found in one of the tanks. In the evening 
when ten cases were visible, the animal was re- 
moved for closer observa- 
tion to a small tank of flow- 
ing sea-water in the labor- 
atory. By the next even- 
ing there were sixteen cases 
in sight, and on the even- 
ing of the 6th, twenty-four 
cases. 
The spawning proceeded 
steadily and the protrud- 
ing egg-cases were counted 
each evening. On the 7th, 
twenty-nine cases had ap- 
peared, on the 8th, thirty- 
five, on the 9th, forty-two, 
on the 10th forty-eight and 
on the 11th, sixty-three, 
when the string of cases 
seventeen inches in length 
was complete. The length 
of shell of the mother 
whelk was eight inches. 
During the whole eight 
days process of egg-lay- 
ing, the whelk rested on the 
ZOOLOGICAL SOCIETY 
SECOND DAY. 
BULLETIN. 
bottom of the tank with the 
open side of the shell 
turned upward and the 
soft parts but slightly pro- 
truding. The position was 
not changed at any time, 
but when the egg laying 
was completed, the animal 
at once turned and attached 
itself to the glass front. 
In nature the whelk buries 
itself in the sandy bottom 
at spawning time, the 
string of egg-cases push- 
ing up through the sand as 
they are cast off. 
Professor Jungersen 
of the University of Co- 
penhagen who called at 
the Aquarium a few days 
later, inquired as to the 
exact portion of the body 
from which the egg-cases 
had been cast off, stating 
that in his opinion, “Cunningham’s explanation 
on this point was incorrect.” It is to be re- 
gretted that the animal was not dissected before 
the conclusion of the spawning in order that this 
point might have been determined. 
Each egg-ecase of the whelk contains several 
embryos, which after a period of development, 
escape from their membranous case to lead in- 
dependent lives. 
CHANNELLED WHELK SPAWNING. EIGHTH DAY. 
The egg-cases are shown floating diagonally across the picture. 
Photo by L. B. Spencer. 
