144 SEA FISHERIES 



accordingly choose what temperature they will. When 

 the young fish enters the pond it is rarely more than 

 2j inches long. It is allowed to grow for two or three 

 years, and then weighs from i to ij Ibs. M. Millet esti- 

 mates that a batch of 1,000 mullet fry will in two years 

 furnish a ton of food. An acre of fishpond produces about 

 3 cwt. of fish each year. The fish are captured from Sep- 

 tember to Easter. They are taken in nets with meshes of 

 1*3 to r6 inches. The sluice is used to catch the eels (the 

 outer frame is placed there for that purpose) ; in the course 

 of March they are speared with five-pronged eel-spears. 



The fishponds of Arcachon are the largest in France, 

 though not the only ones. About 1866 M. Battandier, 

 of Marennes, transformed his salt-marshes into fish- 

 ponds. This transformation is becoming less and less 

 uncommon on the Atlantic coast of France, for the 

 preparation of salt is becoming less and less profitable 

 since the intensive exploitation of the mines of rock-salt 

 and the development of the Mediterranean salt-pans. 

 Dr. Kemmerer, of the He de Re, has sacrificed some of 

 his oyster-parks by transforming them into fishponds 

 for mullet, eels, soles, turbot, red mullet and sardines. 

 The best-known fishponds to-day are those of Primel 

 at Morlaix, Pont-1'Abbe, Concarneau, Lorient, Les Sables, 

 and 1'Eguille. At Trinite-sur-Mer, M. Despommiers has 

 constructed some excellently equipped aquaria, to which 

 I shall presently return. The fishponds of Sables- 

 d'Olonne, or "fish-marshes" established at the mouths 

 of the little watercourses, deserve a special mention, 

 They differ from those of Arcachon in that their sluices 

 are quite rudimentary; they consist of boards sliding 

 between two parallel grooved uprights. One of these 

 boards is pierced with an aperture in which is adjusted 

 a device analogous to the "sleeve" of the Arcachon 



