28 ish Cultural Association. 
I. THE MIGRATORY HABITS .OF FISHES. 
I. THE MIGRATIONS OF FISHES AND BIRDS COMPARED. 
Ir was formerly believed that all seasonal migration was 
directed toward and from the equator, but zoologists of the 
present day recognize another kind of migration quite as im- 
portant, although usually not so extended. At the approach 
of the hot season in sub-tropical climates the birds seek a cooler 
temperature, either by flying northward or by ascending the 
high mountains. In like manner the fishes of any region may 
find water of suitable warmth by moving north or south along 
the shores of the continent, or by changing to waters of less or 
greater depth. The former may be called equatorial migration, 
and the latter bathic migration. 
Il. BATHIC MIGRATION. 
Bathic migration is the most common. The cod family, 
the halibut and flounders, the scuppaug, tautog, sea-bass, and 
sculpins, are well-known examples. The cod prefers a tem- 
perature of from 35 deg. to 42 deg. F., and this it secures in a 
temperate climate, such as that of Southern New England, by 
remaining on the off-shore banks in 15 to 35 fathoms of water, 
coming near the shore in winter, On the coasts of Labrador, 
Newfoundland, Nova Scotia, and Eastern Maine they are near 
the shore in summer, and in deep water in winter. In Norway 
they are caught, to some extent, in the fiords in the summer 
season, though never in winter: in summer they still remain 
on the off-shore banks. The halibut move up and down on the 
sides of the great oceanic banks and the continental slopes with 
the seasonal changes of temparature: in the summer they are 
abundant in the shallows of South Greenland, while in winter 
they are in deep water. On the coast of Massachusetts they 
