514 THE ZOOLOGIST. 
As regards the age of Trout, a personal experience is given 
of one which had passed nearly twenty years in confinement. 
Trout show decided preferences for colours; but our author does 
not consider, as many do, that a certain colour is more deadly 
because more readily seen, but rather ‘‘ We believe, in most 
circumstances, the sky above and the water combined gives a 
better guide, and that the converse of Stewart’s theory is the true 
one, viz. that ‘a certain colour is more deadly because less readily 
seen,’ and that movement is the more visible sensation to the eye 
of afish.’’ And further on we read that anglers of experience and 
with sufficient scientific interest in their practice believe in “a 
dark fly in a dark water and sky, and a light fly in a bright water 
and sky.” We will only give another quotation: ‘‘If a large 
Trout is on the prowl, or has taken up his special feeding-lie in a 
stream, he commands the ‘key of the situation,’ and is not 
slow to repel all minor fry that come within many feet of his 
‘monarchical throne.’ This we have often seen when looking 
down into the clear water from a height. Even before taking 
the bait himself he will chase away the small fry, 2.¢. if the bait 
is lying stationary at his very nose.” 
Faune' de France, contenant la description des espéces indigénes 
disposées en tableaux analytiques et rllusirée de figures re- 
présentant les types caractéristiques des genres. Par A. 
AcLtoqut. Paris: J. B. Balliére et Fils. 
Tuts is the third volume of a series descriptive of the Fauna 
of France; those preceding were principally devoted to the 
Insecta. The present volumetreats of the ‘“‘ Thysanoures, Myrio- 
podes, Arachnides, Crustacés, Nemathelminthes, Lophostomés, 
Vers, Mollusques, Polypes, Spongiaires, and Protozoaires.” 
The method pursued is a synoptical one. The structural 
characters are given from class to species, very many of the 
genera are figured,—in fact, there are 1664 figures in the volume 
now before us,—and the most salient characters are sought to 
differentiate throughout. The labour expended in this work 
must be prodigious; for what monographer does not remember 
the travail incidental to the formation of a synoptical key to 
