MARINE FISHES OF MASSACHUSETTS. 517 
same locality or fishing-ground. This fish does not migrate 
along the coast, but acquires its desired temperature by 
gradually moving from shallower to deeper water, and re- 
turning as the season grows colder. Nearly all fish which go 
in schools migrate more or less along the coast after coming 
from the deeper water, while those which are distributed over 
the bottom, as the Cod, Haddock, ete., do not migrate ex- 
cept from shallower to deeper water. 
Codfish visit the shallow water of Massachusetts Bay to 
spawn about the first of November, and towards the last of 
Fig. 110. 
The Haddock, Morrhua xglefinus. 
this month deposit their eggs on the sandy banks and rocky 
ledges.* About eight or nine millions of ova are annually 
deposited by each füindlé/ The codfish remain in the vi- 
cinity of their eggs till June, when they again retire to 
deeper water, the shallow water having become too warm 
for them. 
The codfish, like the mackerel, takes no care of its eggs, 
and only a small portion of these ever arrive at maturity. 
Nature so regulates the destiny of these eggs that only a 
portion of them are permitted to mature, prm the 
* G. O. Sars of Christiania, Norway, has observed that codfish deposit their spawn 
at the surface of the water, where the fen float throughout the whole of their develop- 
ment. He has followed up the evelopment a the egg, and as fa young, during the 
first fortnight after exclusion. The the egg 16th day. See Giin- 
ther’s Zoological Record for 1868, — EDITORS. 
