182 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



not sucb heavy deposits of sand, &C.5 and as oysters are found in the 

 Adriatic at a deptb of 30 to 40 meters [abont 20 fiitboms].* On the 

 other hand, we know that young oysters have become attached, in the 

 sea near Tarauto, to fascines i)hiced on banks at the depth of 30 meters. 

 As regards fresh water, facts have proved that it is not injurious to the 

 life of the oyster. 



We perfectly agree with Chevalier Bullo in his advice that the la- 

 goons are to be preferred to the coast. Professor Issel, speaking of 

 oyster culture in the Mediterranean, says that the places destined ibr 

 oyster culture should be well protected from the direct action of the 

 waves. The most suitable places should be looked for in tlie estuaries, 

 and especially in those parts of the lagoon which are nearest to the sea, 

 and where it is safe to assume that the water is continually renewed. 



Another reason in favor of this selection must be found in the fact 

 already referred to that the oysters from the quiet waters of the lagoon 

 have a far better tiavor than those from the sea, and are therefore more 

 sought after by dealers. 



The above-mentioned conditions are not easily found, and I can state 

 that one of the very best locations is the one of which I shall now speak. 



It was the intention of Messrs. Grego to devote a portion of their 

 ])roperty to the reproduction and raising of oysters, and eventually of 

 other mollusks. 



The most favorable region, at least for the raising of oysters, is cer- 

 tainly the swamp of Dossetto, and this entire region is called II MerJo. 



In visiting this pond we entered through the principal canal, about 

 four meters deep, which emj^ties directly into the swamp. On its side 

 towards the sea it has a breadth of about 100 meters, but including 

 also the land alongside of the water its extent is about 1 kilometer. 



Owing to the proximity of the sea, the water is continually renewed; 

 and, although the average depth of the lake is only 32 to 35 centimeters, 

 the dangers arising from stagnant water do not exist, viz, the higher 

 temperature and increased saltness, which in numy of these swamps 

 do a great deal of harm to lish-culture. 



The bottom of the jDond presents all llie conditions which are neces- 

 sary for the successful raising of mollusks, although a greater depth 

 would be desirable. There are large portions entirely destitute of 

 marine vegetation, while others are rich in plants, particularly Zcstera 

 liana, which I i'ound fresh and healthy notwithstanding the heat of 

 summer to which they had been exposed during several months, which 

 is another fact tending to show that the temperature of the water is 

 not very high. 1 observed here and there shells of different mollusks 

 {Trochus^ Cardinm, &c.,); and alive 1 found Cerytlmim afrum D. S., JVffi«,srt 

 prismaiica, TrochuH albi(h(s, Mytilus gallo])rovincialis (all young individ- 

 uals), and some other species common in such places. 



*Sonie were also caught about the middle of the Qtiarnero. 



