NOTICES OF NEW BOOKS. 445 
‘innumerable rises.” ‘On closer inspection these will prove to 
be fish taking what I believe are called the nymphe of the Duns or 
Mayflies just before they reach the surface, there to hatch out.” 
Col. Custance deals somewhat exhaustively with Trout- 
breeding. ‘‘ The three principal breeds of freshwater Trout 
raised by the British fish-culturist are the English Brook Trout 
(Salmo fario), the Loch Leven Trout (S. levenensis), and last, but 
not least, the Rainbow Trout (S. irideus). 'The first is the one 
used for general stocking purposes in this country ; S. levenensis, 
although a lake Trout, will also thrive in rivers where there is a 
considerable depth of water; but Col. Custance gives his vote 
for the Rainbow Trout, which originally came from America. 
He describes it as almost satisfying ‘“‘ the Trout-breeder’s ideal 
of perfection.” ‘A splendid surface feeder, he will readily 
accommodate himself to new water, and will, under favourable 
conditions, grow with extraordinary rapidity and to a great size.” 
S. urideus has a common frailty of the Salmonide in-a pro- 
pensity to cannibalism, but he is considered to have less of that 
quality than S. fario, but this is owing to the Rainbow Trout 
having the smaller mouth. 
We may say that the authors of this little volume are anglers 
among naturalists, and naturalists among anglers. 
