400 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
secured in the rivers Blackwater, Crouch, and Colne (below Colchester) by a regular 
process of harrowing the bottom during the beginning of the spring. By this means 
the loose sediment accumulating during the winter is broken up and carried off by the 
tide. For this operation a harrow is prepared whose teeth, 2 or 3 inches in length, 
are of iron, bent slightly forward at the tips. When in use it is carefully arranged so 
that the teeth may not break through the crust which was formed by the shelling 
processes of former years; this is prevented by adjusting the length of the harrow 
rope from the dredging vessel, and the behavior of the harrow, like that of a dredge, 
is readily determined by the “feeling” of the rope. 
Along these rivers tidal pits dug out mainly in open ground are very frequently 
employed. Their use is principally for storage during the winter and early spring, as 
it is said that serious losses are then caused by the freshening of the rivers at low 
tide, “ when the oysters are so weakened that they become particularly sensitive to 
frosting.”* In regions where the water is considerably salter, as at Falmouth (60° F., 
1.0265, August 10), pits are not generally employed. In some instances they are used 
for providing temporary shelter. 
A brief notice may be given of the commoner varieties of oy.sters of the English 
market. The highest grade is the “Native,” Whitstable, Favershain, Briglitlingsea 
(Colchester), a small oyster measuring 2g by 24 inches, with a smooth, thin, pearly shell, 
having a firm, smooth margin, valve outline stoutly crescentic, animal well “fished” 
(fattened), white ; retail price about 4 d. apiece. The Burnham native, “Button oyster,” 
or “Tom Thumb” is highly esteemed; it is remarkably small, stout, and heavy, and 
appears to be of extremely slow growth; individuals at least 15 years old have 
been noted. The majority marketed are of undoubted French origin, having been 
for a longer or shorter time laid down in English waters. These are comparatively 
low in price, and are known under various trade names — Royal, Victoria, Seconds. 
Arcachons, Aurays — usually to be recognized by their shape and by the circular mark 
upon the shell, often with adherent cement, showing where the seed oyster was for- 
merly attached to a collector. This, too, is one of the marks of the small oysters from 
Ostend. Large, rough-shelled North Sea oysters are not uncommon. The cheapest 
grades are the American and Portuguese. Of the former, those that the writer has 
seen appear to have been of southern origin, similar to those largely planted in the 
waters of Long Island Sound; when laid down in English waters they grow rapidly 
and become exceedingly “well fished”; their color, however, appears to change from 
white to leaden gray, and the taste becomes metallic, resembling that of the Portuguese 
oyster. The American species does not appear to spawn in the English waters, 
although some specimens examined by the writer at Whitstable were with well- 
developed ovaries and appeared to be almost in spawning condition. The price of the 
best relaid American oysters is about 40 shillings per 1,000. Portuguese oysters 
retail at about half of this price. They grow very rapidly, an instance of a growth 
of 4 inches in two years being recorded. Their spawning in the Medway, at Skarfleet, 
has been observed.! 
The oyster industry in England, it will be seen, is established on a different 
footing from that on the Continent. It has developed characteristic features, owing, 
in a large measure, to the difficulty with which any fishery rights may be taken from 
the people. Not that there has been a lack of interest on the part of people or 
* This was stated by Mr. Newman, Colchester, August 16, 1892. t Philpots, loc. cit., p. 355. 
