HIND, ON THE FOOD OF THE MACKEREL. 293 



coast. In the same manner they meet and follow the capliu, guided no doubt by the peculiar odor 

 developed by each species at the approach of the spawning season. 



"But it is the habit of the sand-eel of burying itself iu the sand between the tides, or iu sub- 

 merged sand beaches, that leads the Mackerel so close inshore. 



"There can be little doubt that a similar indraught and outdraught of Mackerel and other 

 fish occur in oiir waters when the launce leave the deep sea to approach the land, or when they 

 return to the deep sea again. Unlike many of the shrimps and larval forms on which the Mack- 

 erel feed, which are drifted to and fro by winds and currents, the lauuce is independent of the 

 wind; but it is only in certain favorable localities frequented by this fish that the burying process 

 between tide-marks, from which it derives its name, can be easily effected; hence, these resorts are 

 not only valuable as bait grounds, but generally noted mackerel grounds, such as Seven Islands, 

 and some parts of Bay of Chaleur, and part of the gulf coast of New Brunswick. 



"This bait-fish approaches the sandy beaches fringing the shores of the gulf in the early sum- 

 mer mouths to spawn; aud here the Mackerel are found pursuing them while engaged in deposit- 

 ing their comparatively large reddish-colored ova on the sands between high and low water. 

 Hence, during flood tide, aud in the lauuce season, Mackerel are commonly taken close inshore on 

 these coasts, in pursuit of the launce; and the best catches are said to be made during the period 

 of high tide, for the following reason: In dull, cloudy weather the lauuce buries itself in the sands 

 left bare by the ebbing tides; but iu bright, hot weather it rarely seeks the shelter of the sand, 

 except near low-water mark, probably because the heat of the sun would be oppressive. The 

 breadth of sandy ground iu which the launce buries itself for the brief period between high and 

 low water marks is thus dependent upon the clearness of the sky. 



"A continuance of cloudy weather is conducive to this kind of close inshore fishery; whereas 

 a bright sky, and a day with a drying wind, leads the launce to select the narrow bands of sandy 

 beach near the margin of ebb-tide, which always remain moist. In cloudy weather with a moist 

 wind, the area in which the launce bury themselves and emerge during the incoming tide is thus 

 very much greater than in bright, hot weather; and it is not uufrequently found by experience 

 that the Mackerel catch in such localities is much greater in cloudy weather than in bright weather, 

 because the bait ground is then far more extensive close inshore. 



"As the summer advances and the launce retire to deep water the Mackerel feed upon the 

 free-swimming and floating embryonic forms of crustaceans ; among the latter the zoea of differ- 

 ent forms of crabs are the most common. Adult shrimps of many species form also a large portion 

 of their food, and the infinite numbers of these forms of life which exist in the sea, from the coast 

 line to a thousand miles from laud, may be inferred from the fact that, together with fish, they 

 form the great staple of food of seals in northern seas. 



"Dr. Robert Brown states that, during the sealing season in Spitzbergen seas, he has taken 

 out of the stomachs of seals various species, of Gammarus (0. Sabini; O. loricatus; G.pingtds; G. 

 dentatus; G. mutatus, etc.), collectively known to whalers under the name 'mountebank shrimps,' 

 deriving the designation from their peculiar agility iu water. 1 



"These small crustaceans are found in countless numbers on the great outlying banks off the 

 North American coast, aud in the Labrador seas they are also in great profusion. 



" It is of special importance to notice that very many if not all of these free-swimming crea- 

 tures iu the sea, from invisible microscopic forms to the largest shrimp, sink to different zones of 

 water or rise to the surface with the variations in temperature and changes in the direction and 

 force of the wind. In fine weather, when the food is at the surface, the Mackerel, the herring, and 



1 Dr. E. BROWN : On the Seals of Greenland. 



