228 FIRST LESSONS IN ZOOLOGY. 



every year; in the prong-horned antelope the horns are also 

 shed yearly. 



The males of such animals as are provided with tusks or 

 horns need them for self-defence in their frequent contests 

 with one another; at the same time, these are organs of de- 

 fence by which the males protect their family, flock, or 

 herd. On the other hand, in the female rhinoceros, some 

 antelopes, the reindeer, as opposed to the other deer, some 

 sheep and goats, etc., the horns are nearly as well developed 

 as in the males. The modes of attack are various : the ram 

 charges and butts with the base of his horns, the domestic 

 bull gores and tosses any troublesome enemy, while the 

 Italian buffalo "is said never to use his horns; he gives 

 a tremendous blow with his convex forehead, and then 

 tramples on his fallen enemy with his knees." Darwin 

 also says that male quadrupeds with tusks use them in a 

 variety of ways: thus, the boar " strikes laterally and up- 

 ward, the musk-deer with serious effect downward," while 

 the walrus can strike either upward,, downward, or side- 

 ways with equal dexterity. 



The male cat is a little larger than the female, and in 

 most mammals the males are usually larger when there is 

 any difference in size; this is seen in the eared seals, in the 

 ox, Indian buffalo, and the American bison, as well as the 

 lion. The mane of the latter adds to its appearance of 

 greater weight and bulk, and Darwin says that the lion's 

 mane "forms a good defence against the one danger to 

 which he is liable namely, the attacks of rival lions." As 

 regards distinctions in color, male ruminants are most liable 

 to exhibit them. In the Derbyan eland the body is redder, 

 the neck much blacker, and the white band separating 

 these colors broader than in the females. In the Cape 

 eland the male is slightly darker than the female. In the 

 Indian black-buck the male is very dark, almost black, while 

 the female is fawn-colored: male antelopes are blacker than 

 the female. The Banteng bull is almost black, while the 

 cow is of a bright dun. Among the lemurs the male of 



