184 BULLETIN OF THE UNITED STATES ElSH COMMISSION. 



From my preliiiiinary ob.servatious I have reached tLe couclusioii 

 that there is some diiierence between the two localities Falconera and 

 Baseleghe. Owing to various untoward circumstances,* however, 1 was 

 not able to take all the observations necessary for forming a definite 

 opinion, and I must, therefore, for the present at least, refrain from pro- 

 nouncing an opinion on the subject. 



I hope during the coming year to make all the necessary observations 

 on the saltness, the temperature of the water, «&c., without which it 

 will be impossible to pronounce a satisfactory ox)inion on the suitable- 

 ness of different places for constructing oyster-pares, and to express 

 my views on the manner in which this useful industry should be intro- 

 duced. 



In oyster culture a distinction should be made between places for re- 

 producing and places for raising oysters ; it is very rare to find a place 

 which is adapted to both these purposes. I think that the swamp of 

 Dossetto is well adapted to the raising of oysters, but I doubt whether 

 they can be reproduced here ; and to get the exact truth of the matter, 

 exi)eriments should be made. With the view to make success more 

 probable, I would not hesitate to place this swamj), which is only about 

 200 meters from the coast, in direct communication with the sea by an 

 artificial canal. In this way the renewal of the water would be more 

 complete and more constant. In front and by the sides of the mouth of 

 this canal oyster-pares might be constructed, furnished with small 

 canals, by means of which a suflScient level of water might be main- 

 tained, so as better to protect the oysters from atmospheric and hydro- 

 graphic changes. 



The most suitable depth of water both for reproducing and raising 

 oysters cannot be ascertained without a series of experiments. In the 

 Little Sea of Taranto, and in the lagoons of Venice, where oysters are 

 found, there are seen in some places near the surface of the water the 

 leaves of the Zostera, which grows on the bottom, but near Fusaro, in 

 shallow water, these plants are not so plentiful (so says Issel). But in 

 our case the proi^osed new current would no longer permit the temper- 

 ature to rise too high, and by using little canals for the inclosed spaces 

 intended for reproduction, the excessive current would be avoided, 

 which would carry tlie embryos into the open sea, and prove a hiiulrance 

 to their becoming fixed to shells and other bodies (anything having a 

 rough surfiice), which should be scattered on the bottom.t The free 

 current in the open part of the pond will increase the depth, thus making 

 it still better adapted to the purpose for which it is intended. 



naving observed in the Carrozza numerous medusas, which, in some 

 cases, might prove injurious, I would consider it useful to keep them 



* Among the rest the delay in sending my instruments. 



t If the current is too strong, it will be necessary to provide a larger uuniher of 

 mother oysters, Avhicli it is not always easy^for an oyster cultivator to procure. 



