144 ASSOCIATION OF ORGANISMS—THE WEB OF LIFE 
attire. And there are so many facts supporting the view that the 
females of many animals are influenced by the ornamental endow- 
ments of prospective partners, that the existence of the Law of 
Beauty will be here taken as provisionally proved. At the same 
time it must not be applied to explain facts in too sweeping a 
manner. Every case should be considered on its own merits, and 
our knowledge of animal habits is so very imperfect that it is easy 
to fall into error. It is also necessary to carefully avoid the pitfall 
of unconsciously assuming that the mental endowments of lower 
animals closely resemble our own. There is no reason to think, 
for example, that a hen-bird exerts a deliberate choice in the 
selection of a mate. She may be strongly attracted towards one 
of several possible partners, and beauty of plumage or voice may 
have to do with such attraction, but that is not the same thing as 
“deliberate choice” in the usual sense. 
It is only among comparatively specialized animals that the 
Laws of Battle and Beauty are exemplified, and a few examples 
will fittingly illustrate the subject. 
COURTSHIP AND MATING OF MAMMALS (MamMaALta) 
Tue Law or BattLe.—A complete list of species in which 
the males fight in order to secure mates would be a fairly complete 
catalogue of Mammals, for in this class the question of Beauty 
would appear to be subordinate. One would naturally expect 
combats to be most frequent in cases where the females were 
comparatively few in number, but as a matter of fact it is better 
marked among polygamous species, which are necessarily social, 
though it by no means follows that all gregarious animals are poly- 
gamous. Deer and various other Hoofed Mammals afford good 
illustrations, and as these lead a wandering life it is possible that 
the practice of polygamy has arisen from the desirability of keeping 
a herd together, an end to which it is more favourable than 
monogamy. In nearly all species of Deer the males alone possess. 
antlers, and this is correlated with the fact that they fight 
furiously together in the struggle to secure mates. In the case 
of our native Red Deer (Cervus elaphus) the adult stags live by 
themselves except for about three weeks in the autumn, this being 
the mating-season. Fierce combats are then frequent, that result 
in the discomfiture of the weaker males, some of which may be 
