II COLORATION Il 
be called brightly coloured.. The Bats of the genus Kerivoula 
have been compared to large butterflies, and some of the Flying 
Squirrels have strongly-marked contrasts of reddish brown, white, 
and yellow. The same may be said of the spines of certain 
Porcupines. But we find in the hair no bright blues, greens, and 
reds such as are common among birds. 
There are certain general facts about the coloration of 
mammals which require some notice here. Next to the 
usually sombre hues of these animals the general absence 
of secondary sexual coloration is noteworthy. In but a few 
cases among the Lemurs and Bats do we find any marked 
divergences in hues between males and females. Secondary 
sexual characters in mammals are, it is true, often exhibited 
by the great length of certain hair-tracts in the male, such as 
the mane of the Lion, the throat- and leg-tufts of the Bar- 
bary Sheep, and so forth; but apart from these, the secondary 
sexual characters of mammals are chiefly shown in size, e.g. the 
Gorilla, or in the presence of tusks, e.g. various Boars, or of horns, as 
in the Deer, ete. The coloration of mammals frequently exhibits 
conspicuous patterns of marking. These are in the form of 
longitudinal stripes, of cross-stripes, or of spots; the latter may 
be “solid” spots, or broken up, as in the Leopard and Jaguar, 
into groups of smaller spots arranged in a rosette-fashion. We 
never find in mammals the complicated “eyes” and other mark- 
ings which occur in so many birds and in other lower Verte- 
brates. It is important to note that in the Mammalia whose 
sense of sight is quite keen there should be a practical absence 
of secondary sexual colours. As to the relationship of the various 
forms of marking that do occur, it seems clear that there has 
been a progression from a striped or spotted condition to uniform 
coloration. For we find that many Deer have spotted young ; 
that the young Tapir of the New World is spotted, while its 
parents are uniform blackish brown; the strongly-marked_ spot- 
ting of the young Puma contrasts with the uniform brown of the 
adult ; and the Lion cub, as every one knows, is also spotted, the 
adult lioness showing considerable traces of the spots. 
The*seasonal change in the colours of certain mammals is a 
subject upon which much has been written. The extreme of this 
is seen in those creatures, such as the Polar Hare and the. Arctic 
Fox, which become entirely blanched in the winter, recovering 
