GADID^. 281 



water. The floating eggs and fry are liable to be blown in shore, or destroyed by 

 the action of wind and waves. 



L-ife history. — The young fish, according to Sars's investigations, at first or 

 before the umbilical bag has become absorbed, are most helpless beings, floating 

 on tne surface and tossed about by winds and waves. As soon as this sacj^is 

 absorbed they seek deeper water, where the sea is more quiescent, feeding upon 

 small transparent crustaceans, as " herring food," Calamus finmarcMcus and 

 Temora longicornis. By the end of the summer, and when about an inch in 

 length, they go more inshore, first seeking shelter each under a medusa, Oyanea 

 capiLlata, where they appear to feed upon the minute animals which constitute the 

 food of this Discophora, and which are stupified by its numerous poisonous 

 threads stretching out in all directions. As a return the young cod-fish consumes 

 a small parasitic crustacean, Hyperia, which clings to the medusa by aid of its 

 sharp claws, and even eats deeply into its jelly-like body. These young fish have 

 also been observed fioating about beneath the harmless disk-shaped Medusa 

 aurita, or secreting themselves beneath sea-weeds or other floating substances. 

 Having left the medusse, they roam about for some time near the coast, but 

 being pursued by sea-birds and other fishes, they seek a more stationary mode of life 

 near the coast, where, however, young pollack have generally previously established 

 themselves. As they grow in size they migrate into deeper water, and at the 

 age of one year they are known as Algse fish by the fishermen, because they resort 

 to sandy localities among the algee near the outer coast, at a depth of twenty or 

 thirty fathoms. These very young are of all different shades of colour, from 

 bright red or yellow, if residing among the Laminaria, to a bright green or gray 

 if in more open or sandy places. The very young cod-fish are genuine ground 

 feeders. Respecting the rapidity with which these fish increase in size opinions 

 are divided, but at the Southport Aquarium, some of 3/4 of a lb. in weight, 

 increased in about sixteen months to 6 or 7 lb. each (Jackson). 



Hermaphrodites — have been recorded by Yarrell (Proc. Zool. Soc. 1845, p. 91) 

 and Dr. J. Smith (Proc. Roy. Phy. Soc. Edin. 1864-65, p. 300 and vol. iv, 1870, 

 p. 256). 



Diseases. — I have already alluded to affections of the spinal column, blindness 

 and parasites in the cod (page 274 ante). When out of season they are 

 tormented with sea-lice, while the Lernea hranchialis is often found attached to the 

 gills. When hooked, the borer or myxine, having obtained entrance through its 

 mouth or gill openings, will almost devour its interior, leaving little but the skin 

 remaining. Ofl' the Shetland sand-banks a se.ssile-eyed crustacean, locally termed 

 " bees," JSga tridens, has been observed to behave in the same manner among 

 fish hooked on the long-lines, so that when the fish is hauled up it looks as plump 

 and round as a live fish, only when opened it is found to be full of " bees," and 

 nothing else (J. Anderson). 1 may here mention as one of the causes of 

 destruction of these fishes, that large quantities of the roe is collected and sold, 

 being employed in France and Northern Spain as bait for the sardine fisheries. 



Uses. — I'rom the air-bladder or sounds isinglass may be manufactured. The 

 tono-ue whether fresh or salted is a great delicacy, while from its liver is prepared 

 an oil, first employed as medicine in this country by Dr. Percival in 1782. 

 Irrespective of the foregoing, we are told that the Norwegians give the head 

 along with marine plants to their cows, for the purpose of increasing the yield 

 of milk.* Icelanders feed their cattle with its bones, as the inhabitants of 

 Kamtchatka do their dogs, while after being well dried they are employed as fuel 

 along tlie shores of the Arctic Ocean. 



As food. — The cod of our seas is in the best season from October to the 

 beginning of February (according to Parnell in the Firth of Forth till the end 

 of April), and in its greatest perfection about Christmas, while those of a medium 

 size are most preferred for the table. It has been observed that such as possess 

 the deepest groove along the back of the head, the largest belly, roundest form 

 especially near the tail and sides, and appearing as if they were ribbed, are the 

 best for the table. In Cornwall, those out of season, and recognizable by their 

 * Off the western coast of India shark's flesh is supposed to possess this property. 



