28 INDIAN FISH AND FISHING. 



descend from the Himalayas, have, exclusive of springs, two 

 most abundant sources of replenishment. During the hot 

 months this is derived from melted ice and snow, while during 

 the monsoons the rains assist ; we may then have the hill 

 rivers forming torrents, rising rapidly, and as rapidly subsid- 

 ing, while they possess no contiguous tanks into which the 

 fish can retire. These animals are often peculiar, or endowed 

 with means of existence differing from such as live wholly 

 or mostly in the waters of the plains. Many of the fish are 

 provided with adhesive suckers, situated behind the lower 

 jaw, or placed on the chest, which enable them to fix them- 

 selves against rocks, and so prevent their being washed 

 away by the stream. 



Through the cold months, and generally until the setting- 

 in of the south-west monsoon in June, rivers are at their 

 lowest, some at this period (especially in hilly regions) being 

 merely a succession of pools, united by a more or less 

 insignificant stream, in which limited localities the fish take 

 refuge, and may be easily secured by fishermen. 



Among the artificial causes affecting fisheries in many 

 districts are the irrigation works, which are formed by throw- 

 ing a weir or bund across a river, and diverting a large amount 

 of its water down a main irrigation canal. These weirs are 

 usually built as stone walls across the entire breadth of 

 rivers, and consequently impede both the upward and down- 

 ward passage of fish that are endeavouring to migrate, while 

 should they be sufficiently high, they entirely stop them. 

 Where large under-sluices are present, fish can pass up such 

 when open ; , but up the long narrow ones, as constructed in 

 Madras, the strength of the current renders this impossible. 

 The under-sluices are here closed, except where there is an 

 excess of water, as during the monsoon months ; and as the 

 weirs have no fish-passes, not only is ascent towards the 



