518 THE HABITS AND MIGRATIONS OF SOME OF THE 
codfish would soon monopolize the whole ocean. These 
eggs are eagerly devoured as food by the various animals 
which inhabit the bottom, and the proportion of eggs de- 
stroyed in this and other ways cannot be readily estimated, 
but we know it must be enormous by the comparatively few 
young fish we see. If, during its stay in shallow water, the 
weather should suddenly become cold, and so remain for two 
or three days, the codfish immediately retreats to water of 
some forty fathoms in depth, and does not return till the 
temporary change has passed ; then they gradually seek their 
Fig. 111. 
The Bluefish, Temnodon saltator. 
former resort, which is a depth of fifteen or twenty fathoms. 
The Haddock (Fig. 110) at such times likewise retreats, but 
does not so soon return to its former station. 
The quantity of codfish annually taken does not differ so 
much in the different years as does that of the mackerel, 
yet the amount is somewhat variable. The cause is the same 
in both cases, but as the codfish has a shorter distance to 
come the annual number is naturally less variable. The 
number of codfish existing at the present time does not ap- 
pear to differ from that of twenty or more years ago, and I 
think we are safe in assuming that there has been no percep- 
tible diminution for a century. 
The food of the codfish consists of smaller fish, mollusks 
and crustacea. The bait considered by the fishermen as 
best adapted to their tastes are the common Herring ( Clupea 
elongata), squid, ete., but clams (Mya arenaria and Mactra 
