NATURAL HISTORY SOCIETY OP GLASGOW. 263 



year, and up to 4 \ lbs. the second year. By 1882, these lochs all 

 abounded with trout, but so small as to be not worth catching. 

 The original food supply was marvellously plentiful, tadpoles and 

 fresh-water shrimps abounding, hence the rapid growth. The 

 spawning ground was equally fine and extensive, hence, assisted by 

 the absence of natural enemies, came the increase in numbers ; and 

 hence also the reaction, the too rapid increase of the fish, and rapid 

 deterioration in size, from the consequent decrease of food. Another 

 loch we stocked had poor spawning ground, but a fine extent of 

 good feeding. Here, between 1878 and 1882, trout grew from 

 \ lb. to 4 J lbs., or larger, whilst a fair average is still maintained — 

 viz., about \ lb. 



In a loch near Durness, where formerly there were no fish, — 

 situated at the head of the burn which finally falls down into the 

 dark depths of the Smoo Cave, which was fishless above the fall, 

 but contained trout below it and in the cave, and in the stream 

 of 30 or 40 yards between it and the sea, — there are now abundance 

 in both loch and burn. This year I got 29 trout, 7| lbs., out of 

 burn and loch together. Six trout were caught about 6 years ago 

 below the fall, carried up and placed in the burn, by a native — Mr. 

 MacXeil Campbell, of Smoo. The crofters, while working at their 

 peats, have seen the fish rising on the loch; but the above 

 basket was the first ever taken out by anybody. I may have more 

 to say upon this subject at another time, and there are some curious 

 facts relating to peculiar coloration which are deserving of special 

 treatment. One more instance I will relate. Our party stocked 

 the upper water of a limestone burn, formerly fishless, above a 

 certain fall, by putting in about a dozen trout from below the fall. 

 This was in 1880. In 1882 they had become fairly plentiful, and 

 reached a fair average size, but did not grow so rapidly as others 

 introduced to larger sheets of still water. This experiment appears 

 to me to have a bearing upon a question, as to relative growth of 

 fish in rapidly running water, and in still dead reaches, ponds, or 

 lochs. The feeding in this case was undeniable, and quite equal 

 to that in some of the lochs referred to above. 



/. Observations upon Fish Life-history, and the changes from the 

 period of their birth to that of maturity. — In other words, the 

 history of the development of each species. 



g. Observations upon Fish kept in Aquaria, rate of growth, 

 variations caused by changes to distant localities (as trout to the 



vol. v. T 





