474 The Outline of Science 



automatic means of getting relief and although the paunch is 

 not stomach it is difficult to refrain from suggesting that the first 

 part of the cud-chewing process may be a sort of normalised 

 vomiting. Nowadays the whole series of steps is reflex or auto- 

 matic, but it is interesting to notice that if the cow is disturbed in 

 the middle of its cud-chewing it is not a little put about, and is 

 often unable to resume the process for a considerable time. Such 

 disturbance is of course injurious to the animal's health. 



10 

 Weapons of Mammals 



Many mammals use their teeth, especially their canines, as 

 weapons. The Walrus strikes downwards with tremendous force, 

 the Wild Boar lunges upwards with the canines of both jaws 

 pointing up. In the Asiatic Babirusa the upper canines, though 

 pointing up, are curved so far backwards that they form more 

 of a shield than a weapon. In male Musk-Deer, and in the like- 

 wise hornless but quite unrelated Deerlets, the canines are 

 strongly developed and are used in fighting; in Elephants the 

 great tusks are front teeth or incisors. The use of the six-foot 

 long left canine of the male Narwhal remains obscure. 



Besides their teeth mammals may use as weapons their claws 

 and their hoofs, and various kinds of horns. The Rhinoceros has 

 a horn that belongs wholly to the skin like a huge wart that has 

 become very hard. The horns of cattle, sheep, and deer have a 

 core of bone (growing from the forehead or frontal) covered by 

 an integumentary hollow sheath of horn. In the Giraffe and the 

 Okapi the sheath over the bony outgrowth does not turn into 

 horn. 



The Story of Antlers 



Antlers deserve a place by themselves. They are restricted 

 to stags with the single exception of the Reindeer, where they 

 occur in both sexes. They are not seen in the buck's first year, 



