195 



perature in the water which is moderate nei- 

 ther too high nor too low. Grayling are never 

 found in streams that run from glaciers at 

 least near their source ; and they are killed by 

 cold or heat. Sir Humphrey put some grayling 

 from the Teme, in September, with some trout-, 

 into a confined water, rising from a spring in 

 the yard at Dowton ; the grayling all died, but 

 the trout lived. And in the hot summer of 

 1825, great numbers of large grayling died in 

 the Avon, below Ringwood, without doubt kill- 

 ed by the heat in July. In the northern. Euro- 

 pean countries, char are always found in the 

 highest and coldest waters ; the trout, in the 

 brooks rising in the highest and coldest moun- 

 tains; and the grayling always lower, where 

 the temperature is milder ; and, if in hot coun- 

 tries, only at the foot of mountains, not far from 

 sources which have the mean temperature of 

 the atmosphere. Besides temperature, gray- 

 ling require a peculiar character in the disposi- 

 tion of the water of rivers. They do not dwell, 

 like trout, in rapid, shallow, torrents ; nor, like 

 char or chub, in deep pools or lakes. They 

 require a combination of stream and pool ; they 

 like a deep still pool for rest, and a rapid stream 

 above, and a gradually declining shallow below, 

 and a bottom ^here marl or loam is mixed with 

 gravel ; and they are not found abundant ex- 



