Acclimatization of Freshwater Fish in Algeria. 385 



ceeded admirablj in the basin of Djebel Ouaeli, and have 

 multiplied amazingly. Some were put into the E,ummel ; 

 but the Zouaves, informed of their translation, immediately 

 set to work to catch them, and soon destroyed these new 

 denizens of the river. 



Attempts at pisciculture have also been made in the pro- 

 vince of Algiers, where carp and, more recently, tench have 

 succeeded perfectly in reservoirs. 



At this point, however, the experiment has remained sta- 

 tionary, and no effort to naturalize the fish thus bred has been 

 made. The question, as far as relates to the Salmonida3, 

 appears to us easy to resolve, after the experience gained at 

 Constantine. Fish of this family require fresh arid clear water 

 not charged with calcareous deposits. These conditions are 

 only possible on certain points of the littoral, particularly in 

 eastern Kabylia, and partly in that of Babor, where the 

 streams rise on the sides of high mountains, preserving a tem- 

 perature nearly constant, flowing on a bed of gneiss, granite, 

 or schist, and protected from the rays of the sun by shady 

 forests. 



Unfortunately, on the whole of the littoral of the provinces 

 of Constantine and Algiers the mountain-range is broken up 

 into an infinite variety of little basins, very steep, which only 

 supply running water from autumn till June. An extensive 

 zone of acclimatization cannot, therefore, be anticipated for the 

 salmon family ; and the small volume of water in those waters 

 will not permit the introduction of the larger species ; but the 

 Algerian trout may well be employed to people the few suit- 

 able rivers, where it does not already exist. 



In this zone also an attempt might advantageously be made 

 to introduce fish of other families, especially of the Percidge, 

 which delight in clear and limpid water. In the province of 

 Oran these might succeed in the upper part of the Tafna, 

 which flows over a bed of rocks and gravel. 



In other parts of the country, where even the most important 

 streams sink, during the hot season, to a mere series of pools 

 connected by shallow rills thoroughly heated by the sun's 

 rays, the carp and tench offer the best chances of success. 

 The latter (which, in Europe, inhabits muddy marshes almost 

 dry in summer, without detriment to the quality of its flesh) 

 might support as well as the barbel the calcareous salts which 

 the majority of rivers in Algeria hold in solution, the rather 

 that they would be free from its natural enemies the larger 

 crustaceans and voracious fishes. 



