Bulletin of the united states fish commission. 185 



out of the new caiial by means of fascines, which might also serve as 

 collectors, and of which I will speak below. 



The ordinary dimensions of the oyster pare slionld bo 30 by 20 meters, 

 and the embankment should inclose a quadrilateral space, containinj:^ 

 8 to 10 mother oysters per square meter — that is to say, if reproduction 

 is intended. If the object is merely the raising of oysters, 150 may be 

 placed in the same space. 



On the coast between Baseleghe and Falcouera oysters propagate, and 

 it appears that the number of their enemies is not very great. It is 

 true that 1 noticed the usual Murex, wliich devours marine shells; but 

 which, as it seems, gives the preference to the Venns. I did not, how- 

 ever, see a single oyster shell pierced by a Vioa or Clione. I believe 

 that tlie Garcimts, the Pagurus, and the Asterina, which abound here, do 

 not do any harm to the oysters, and I cannot share the opinion of De la 

 Blauchere as regards the first- mentioned sj)ecies. 



Oysters are likewise reproduced in the Canal Canadare, and it would 

 be well to put collectors in both places for a trial. I would always give 

 the preference to fascines, similar to those used at Taranto — i e., about 

 2 meters long and 1 meter in circumference — proper care being taken 

 not to have too thick stems and too thin branches. 



Fascines tied with a cord or zinc wire are to be preferred. They 

 should be raised somewhat above the ground, and attached to a large 

 rock by a cord of broom-corn. 



Another practical method is to use pales covered with hydraulic cem- 

 ent, mixed with sand ; but they have the disadvantage of jiresenting 

 fewer points for fixation to the embryos while being carried along by the 

 currents. 



A third kind of collector which I proposed, because I think it is well 

 adapted to many points in the localities visited by me, might be formed 

 by a pale, if desirable, covered with cement, to which at a certain height 

 fascines are attached. All that is required would be to ram the lower 

 end of the pale, which should be ])ointed, into the bottom in a neighbor- 

 hood where there are mother oysters. When the young oysters are to 

 be trai;^ported these pales are simply pulled out. I advised Messrs. 

 Grego to place some of these collectors near the mouth of the canal, 

 which leads to the principal canal of Val Nova. 



As regards the spawn, I would always prefer that from the lagoon. 

 There is no difficulty in procuring mother oysters, because they are 

 quite frequent in many places of the estuarj' ; and when it is remem- 

 bered that one oyster can furnish from 000,000 to upwards of a million of 

 embryos,* there is no fear that the principal elements of oyster culture 

 will ever be wanting, and that the experiment will prove a failure, pro- 

 vided the locality selected is favorable to the life and develoi)ment of 

 the oyster. 



* Davaine : Jieclierches sur la generation ilea hiulres. Paris, 1853, p. 45. 



