PROGRESS IN BIOLOGICAL INQUIRIES, 1926 607 
back when the bottom stage is reached, or both. Perhaps the young bottom 
stages entering the shore waters south of Cape Cod with large schools of small 
pollock, each spring, represent survivors from the bay. 
Unfortunately, it was not possible to continue the work long enough to deter- 
mine whether the eggs that enter past Cape Ann hatch within the bay. AlIl- 
though of interest, I do not think this would alter the problem, because the 
same current that carried them in would transport them out again. 
Various investigators have shown that the fry often are transported for 
tremendous distances, and the few that might reach their benthoniec stage 
during the interval between Cape Ann and Provincetown probably would not 
affect seriously the natural economy of the area. 
It is to be expected that some of the cod eggs drifting west from the Gulf 
of Maine will hatch before leaving Massachusetts Bay, and there is some evi- 
dence of this. Doctor Bigelow has found cod larve in the bay; and Mrs. Fish, in 
examining two 45-minute plankton hauls (top and bottom) made by Mr. Iselin 
i mile east by south of the Boston Lightship on June 5, 1926, found 122 cod 
lary, 4.5 to 9 millimeters in length, in the haul from 8 fathoms (temperature, 
39.5° F. at 10 fathoms). No larve were found in the surface net, but an 
abundance of eggs was present in both. 
Certain peculiar conditions were observed early in the bay. We saw very 
soon that the eggs were disappearing before they hatched. We took thousands 
of eggs on these trips at all stages of development, but never a young cod. 
Two results were obyious—either these eggs were being destroyed before they 
hatched or they were drifting out—so drift bottles were placed at various places 
in the bay and at the same time the eggs were plotted. The distribution of eggs 
at each station and the percentage of eggs at four stages of development were 
taken. Later, to avoid any confusion in distinguishing between early and 
late cleavage and to note any line of demarcation, we divided into cleavage 
and embryo stages and plotted them. That showed very definitely a movement 
from the Plymouth Banks around the inner arm of the bay. At some times 
it appeared that the eggs were following close to the lower island and in 
others they seemed to be drifting across to other stations. The drift bottles 
also indicated the same drift. Of those placed along the lower arm almost 
all were found five or six days later either along the inner arm or in Province- 
town Harbor. Those that missed the top of Cape Cod went out and divided, 
part drifting southeast and part to the north. Those turning to the north 
followed the same general direction as the bottles placed by previous investi- 
gators. It seems that the rate of drift was somewhat slower—I believe about 
4 miles a day. According to the records on the return trip they did not 
do much more than 175 miles a day. 
The records made by Doctor Bigelow on the movements of codfish and 
eggs in Massachusetts Bay give us every reason to believe that this may form 
a very important nursery, because the eggs may find protection and apparently 
ample food, the plankton communities being very rich; and it would- probably 
be an ideal spot, not only for locally spawned cod eggs but for those passing 
along the whole coast of Maine to drift in and develop; and if our observations 
are repeated for another year they will, no doubt, show the same thing. 
The solution of this problem should be sought along two lines. The eggs 
passing out of the bay should be followed. I have computed the rate of drift 
as indicated by the bottles and as indicated by the eggs. The eggs that spawned 
in the Gulf of Maine may drift into Massachusetts Bay and hatch. That 
would not seriously alter the problem, because the same current that brings 
them in would, no doubt, carry them out; and the few that reach the bottom 
in the interval might not seriously alter the general conclusions that very few 
remain there. 
The other possibility is that a great many larve are destroyed in that 
region. In fact, some of the recent papers raise that question whether or not 
the larve are not all being destroyed in the early stages. It may be that a 
great many of them are being destroyed, but the cod investigation shows that 
the cod eggs have been hatching in the bay. The fact that so many of the 
pollock seem to exist there, at least for a time, indicates that they are not all 
wiped out. 
That covers the work to date, except that there is one other little indication 
that at times large numbers of cod larve come into the bay. Some experi- 
ments were made after the conclusion of our work near the Boston Lightship 
by Mr. Iselin on June 5, and he found in one bottle, at 10 fathoms, 122 cod 
