72 SALMON I A. 



SO all the summer; and this river is fed 

 by streams from snow and glaciers in the 

 Tyrol, and is generally foul : whilst the small 

 spotted common trouts, which are likewise 

 found in this lake, go into the small brooks, 

 which have their sources not far off, and 

 in which, it is probable, they were originally 

 bred. I have seen taken in the same net 

 small fish of both these varieties, w^hich 

 were as marked as possible in their cha- 

 racters : — ^one silvery, like a young salmon, 

 blue on the back, and with small black spots 

 only ; the other, with yellow belly and red 

 spots, and an olive-coloured back. I have 

 made similar observations in other lakes, par- 

 ticularly in that of the Traun near Gmiinden, 

 and likewise at Loch Neah in Ireland. In- 

 deed, considering the sea trout as the type of 

 the species tr^cmt^ I think all the other true 

 trouts may not improperly be considered as 

 varieties, where the differences of food and 

 of habits have occasioned, in a long course of 

 ages, differences of shape and colours, trans- 

 mitted to offspring in the same manner as in 



