216 SALMONIDvE OF BRITAIN. 



In some "waters it lias been held that not killing eels is very destructive to 

 trout, consequently, night-lines should be permitted. Eels in some localities are 

 more mischievous than in others, while otters are said to be very partial to eels. 

 It is stated, in the forty-sixth Report (1883-84) of the Thames Angling Preservation 

 Society, that, "as regards the trout, -which, previous to the abolition of night-lines, 

 were gradually diminishing, there is now an abundant supply, and the past season 

 has afforded substantial evidence that those fish are yearly increasing in numbers 

 and the prestige of former days returned." 



Habitat. — The colder and temperate portions of the northern hemisphere, 

 descending in Asia as far south as the Hindoo Koosh, but not normally present in 

 any portion of Hindostan. Heber, mistaking a spotted carp, JBarilius, for a trout, 

 asserted they were found on the Himalayas, on which authority Couch gave India 

 as one of its habitats. It has been introduced on the Neilgberry range of hills in 

 Southern India, where most of the examples were transferred to the rivers on the 

 Koondah range. It has also been artificially introduced into many countries in 

 the southern hemisphere. In the Oi'kneys it is found in great numbers in every 

 burn, and generally extended throughout the rivers and lakes of the British Isles 

 when unchecked by pollutions. Some exceptions, however, to this general rule 

 would seem to occur. In Norfolk it is found in small numbers in the higher parts 

 of the Bure, the Ware, and some of their tributaries, but not in the Waveney 

 (Lubbock). 



As to the size it attains, in 1880 Buckland made a cast of one 17 lb. weight, 

 captured at Reading, July 1 1th, 1882, one 20 lb. weight was secured in Lough 

 Derg, an expansion of the Shannon (S. Hurley) : while the so-called S. ferox has 

 been taken up to 50 lb. weight or even moi'e. In the Thames, close to the mouth 

 of the Kennett, one was taken on April 24th, 1880, weighing within one ounce of 

 17 lb. ; on May 18th, 1863, a 15 lb. one was caught in Marlow Weir pool ; and on 

 May 21st, 1883, Mr. Ross Faulkner caught a 14 lb. fish at Hampton Court. If 

 this fish has abundance of space, unlimited food, and is permitted to b've out its 

 existence, it would doubtless arrive at as great a size as was formerly recorded from 

 Irish lakes. 



ADDENDA. 



Since the foregoing went to press, through the kiudness of Mr. Willis-Bund, 

 Lord Lisbuime and Dr. Rowland, I have been enabled to investigate in Cardigan- 

 shire some of the apparent causes afi'ectiug the number of caeca, a detailed account 

 of which will be published. In the three lakes situated in the hills and which 

 form sources of the Teifi we found in five from Llyn Teifi, two males 33, 40, 

 three females 35, 39, 41 : in five from Llyn Hir, three males 37, 41, 43, in two 

 females 48, 52 : in five from Llyn Egnant, four males 33, 43, 44, 48, one female 

 42. In the upper portion of the Brefi where the stream is narrow, running between 

 rocks, and the contiguoiis land is uncultivated, five trout, with very little fat on 

 their cfeca, one male 35, ioviV females 34, 35, 36, 41. In the last two miles of tlie 

 Brefi, the sides of which are cultivated, six fish, three males 33, 38, 45, three 

 females 41, 41, 50. In the Teifi, fourteen trout, seven males 38, 41, 41, 41, 46, 

 46, 48, seven females 39, 40, 42, 45, 45, 47, 49. Average in Teifi fish, 43 ; in 

 lower or cultivated portions of its affluent, the Brefi, 41 ; in its higher or 

 uncultivated part, 36; in lakes at its commencement, Llyn Teifi, 37; Llyn Hir, 44; 

 Llyn Egnant, 42 : or the least number being where the least iimount of food existed. 

 In Llyn Berwyn, a lake at the head waters of one of the tributaries of the Towy, 

 of two fish, a male had 42, a female had 42 : in the narrow and rocky Pysgotwr 

 having uncultivated sides, and which flows into the Towy, out of nine fish, five 

 males had 28, 35, 35, 35, 37, and ionr females 32, 35, 36, 40, or a general average 

 of 35, again showing that with paucity of food a diminished number of ca3ca 

 co-existed. (See p. 199 arite.) In three of the Teifi trout I found two had each 

 56 -f- x vertebra) and one had 57 -{- .t. 



