EUROPEAN METHODS OF OYSTER-CULTURE. 
365 
massive sluiceway projecting into the sea. (PI. lxxvii, Fig. 2.) The present estab- 
lishment would rival in quality, if not in size, its predecessor, famous in imperial Borne. 
Monte Nuova, which sprang up in 1538, is supposed to have greatly reduced the ex- 
tent of the lake and destroyed its ancient prosperity by volcanic ejections. Lucrinus 
is rich in its associations, and is even to-day in the possession of the family of Pollio, 
which has long held the property, and may represent the Roman Pollio, whose villa, 
with accompanying collections of ceramics and slave-fed murcenas was undoubtedly iu 
the immediate neighborhood. 
Like Fusaro, Lucrinus has its waters perceptibly freshened, but its salinity can be 
better regulated. At one end of the lake a small canal leads a few hundred feet to a cir- 
cular pond practically of fresh water, fed by bubbling hot springs (temperature as emerg- 
ing, 104° F., sp. gr. 1.004); this is connected with a second basin of a bubbling spring 
(sp. gr. 1.010 at 00°) of slightly greater salinity. To these sources of freshened water 
should be added a deep spring in the neighborhood of the ateliers (PI. lxxvii, Fig. 1). 
Lucrinus has but a single disadvantage iu that its small size restricts its cultural limits, 
its extent being but about 10 acres. Proportionately its depth is greater than Fusaro, 
its basin shelving gradually to about 16 feet, and the bottom is less muddy, consisting 
mainly of tufa and sand. Its waters have a density of 1.0225 to 1.0245 at 79° to 80° F. 
Its temperature was the same as that of Fusaro, its greater depth and its constant 
communication with the outer water tending doubtless to maintain a greater uniform- 
ity in this respect. In the winter season the influence of the hot springs becomes of 
great service, favoring the growth both of the oyster and of its vegetable food. The 
proprietor of the lake, Oav. Domenico Pollio, favors the continuous introduction of sea 
water. The fall of tide (20 to 30 cm.) is sufficient to allow a proportion of water to 
pass out and to be replaced. This system has its effect doubtless in preventing the 
water volume from becoming either too fresh or too warm, and indeed the amount of the 
incurrent fresh water would render it decidedly dangerous to close the floodgates for 
any considerable time. It is, therefore, not remarkable that spat-collectiug has never 
been permanently regulated. The yearly success has remained dependent upon favor- 
able conditions of season, i. e., a season producing a sudden and complete spawning, 
shortening the embryo’s swimming stage, and reducing thereby the chances of the 
escape of the fry through the sluiceway.* 
Culture is carried on by the usual method. The stakes, seen in PI. lxxvii, Fig. 1, 
support a mesliwork of ropes bearing fascines and baskets. Collectors of all varieties 
are brought into play, bunches of tiles roughly fastened together, and flat stones 
even being often included. Elevage is doubtless the cultural strength of Lucrinus, and 
the flattened wickerwork trays filled with half and full grown oysters are suspended 
at every possible point of support. The growth appears to be phenomenally rapid ; a 
second year is said to be sufficient to produce an oyster 3.1 inches in diameter. The 
Genoese oyster ( O.plicata ) is occasionally produced, being known here as the Ostra 
reale , and is exquisite in color and flavor. Other shellfish are naturally abundant in 
the basin, the vongala [Tapes) being of especial commercial value. The fish supply 
entering daily from the sluiceway during the falling tide is often of considerable value. 
The seriola, suggestive of Roman dinners, is especially abundant here. The straw 
runway which allows fish to enter and not to escape, will be noticed in PI. lxxvii, Fig. 
1, photographed from the bridge over the sluiceway. 
* Granting that an embryo would have a greater chance of escape in 48 hours than in 4 hours. 
