Gobio. INDIAN CYPRINID^. 365 



salt-water. They are all used as a wholesome food by the people of India ; 

 few of them however attain any very great size, or are much esteemed for 

 their flavour by the wealthy. There is reason, I must observe, to believe 

 that the quality of their flesh varies occasionally according to the ponds from 

 which they are taken. 



As they do not prey upon each other, the size of the water into which 

 they are introduced is the only limit to the extent to which they will propa- 

 gate, provided merely that the Siluridcs and similar carnivorous kinds be not 

 allowed to flourish in the same ponds. If the proprietors of tanks were only 

 to allow their fishermen to take the destructive kinds from their ponds for a 

 season or two, such as the various kinds of Magu?', Pahda, Singhi, Boalis, 

 Aoar, Sal, &c. they would then find the 3fr/gala and other Bangons so 

 numerous, as to repay the little attention required to prevent their destruc- 

 tion. In Bengal fishes are so abundant that perhaps any great augmentation 

 of their numbers is little to be desired ; but in the North-western Provinces 

 the case is very different, especially where there are few tanks and streams ; 

 and these I have found to be almost entirely abandoned to Pikes and other 

 rapacious species, such as cannot allow the more profitable kinds to multiply, 

 where, from a scarcity of water they ought to be preserved with the greatest 

 care. When fishes are too much crowded in ponds, they are liable to 

 epidemics. In June last, Mr. James Prinsep sent to me a number of Bangons 

 from a pond at the Mint, in which they had become blind, some of one, and 

 others of both eyes. Mr. Prinsep insisted on investigation of the subject, 

 and with the aid of our friend Mr. J. W. Grant, we found the disease to be a 

 dropsical affection of the membranes of the eye, by which an excess of fluid 

 was secreted so as to cause that organ to protrude beyond the orbits, in some 

 cases almost to the size of an egg. Tiie fishes thus affected were all of the 

 same species, Gobio limnophilns, and all in tlie pond were observed to be 

 seized in the same way. Tlie cause of this singular disease was of course less 



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