CLAM FI8HER Y OF PASS AM A Q UODD Y BAY 33 

 SESSIONAL PAPER No. 22a 



as to form almost the sole object of food of the oyster or clam. Jn other cases it is 

 believed that the coloration is due to a green Desmid (Peridinium) upon which the 

 oysters feed. 



It has lately been shown by Herdman, Boyce and Kohn, of Liverpobl, England, 

 that oysters do possess small quantities of copper, iron, and sometimes manganese, in 

 their tissues. There are several distinct kinds of greenness in oysters ; in animals from 

 certain places this is associated with a healthy condition, but those from other districts 

 may be in an unhealthy state. Healthy French ' Huitres de Marennes ' were found 

 to contain more iron in other parts of the body than in the gills, the greenness of which 

 could not be due to iron. Green Falmouth and other Cornish oysters were found to 

 possess an abnormally large quantity of copper — as much as nine times the normal 

 amount. Among certain American oysters selected green ones were shown to contain 

 3*75 times as much copper as the ordinary white ones, and the distribution of the excess 

 of copper corresponded with that of the green colour. In such cases it is evident that 

 the abnormal green coloration (green leucocytosis) is due to excess of copper. The 

 excess is probably occasioned by a failure to remove the small quantity of copper which 

 ordinarily passes through the system in the form of hsemocyanin of the blood. This is 

 taken up by amoeboid blood corpuscles (leucocytes) which, in the disturbed metabolic or 

 diseased condition of the body, become aggregated in the blood capillaries of the gills, 

 palps, and mantle, or massed in the heart. 



In the mantle cavity of the clam occurs, in certain districts, a parasitic Nemertean 

 (Malacobdella ohesa). Although I have examined clams for portions of two years, and 

 must have opened several hundred, I have never yet found a single individual in Passa- 

 maquoddy Bay that harboured this peculiar worm. It measures 30 or iO mm. in 

 length and 12 to 15 mm. in thickness, and could scarcely be overlooked even if one did 

 not know about it ; but I searched a good number of clams for the express purpose of 

 obtaining this object, without success. The crystalline style, already referred to in de- 

 scribing the intestine, has been pointed out to me by clam dealers in the belief that it 

 was a worm. In this connection T should perhaps mention the possibility of clams 

 obtained from places near which sewers and offal of towns are emptied becoming a 

 vehicle for the transference of bacteria to uninfected people. It has been shown that 

 pure sea-water is detrimental to the growth of pathogenic bacteria, but that oysters 

 inoculated with typhoid bacilli retained these for at least ten days, although they did 

 not increase in the tissues of the oyster. 



2. Clams as Bait. — For nearly four centuries important fisheries for cod, mackerel, 

 halibut, &c., have existed on the ' Banks ' of Newfoundland. Thither, especially New 

 England and Acadian fishermen have been accustomed to resort to fill their vessels in 

 the richest and most extensive cod-fishing district in the world. In the 17th, 18th and 

 first half of the 19th centuries they fished with hand lines from the decks of vessele. 

 About the middle of this century the practice of fishing with hand lines from dories 

 was introduced. The vessels left home in April, May, and June and perhaps for a trip 

 of 2^ to 4 months. In a vessel with a crew of 12 every one but the skipper and the 

 cook was provided with a dory. Thus they could spread over a lai ger area, if any one 

 found a good school of fish the others could flock towards him, and besides it was thought 

 that the motion of the dory gave a quicker movement to the hook rendering it 

 more attractive. It was believed that this method realized one-third more fish but of 

 course there was the extra expense of the dories. 



It was learned long ago that carnivorous fishes such as the cod were especially fond 

 of moUusks. In the stomachs of Newfoundland cod are frequently to be found a shellfish 

 closely allied to My a arenaria. Our soft clam came into use at first for in-shore fishing 

 of various kinds. As the fishing voyages lengthened clams were carried farther and far- 

 ther to sea. They were used fresh, but later they were kept in wells in the vessels, 

 or kept cool with ice. The vessels of Cape Cod, Gloucester and Maine, constituting the 

 largest part of the fleet on the ' Banks ' in the cod and mackerel fisheries, have no well, 

 and are obliged to carry their bait shelled, salted, and packed in barrels. 



The old style of mackerel fishing was to chop up clams and to sprinkle them over- 

 board as ' toll-bait ' to attract the mackerel to the serface. Now mackerel are caught 

 in seines. Cod-fishing is conducted in two ways — by trawling or by hand-lining. In 

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