422 WILD ANIMALS. 



beaming with the keenest power of vision. They also possess a 

 delicate sense of smell, which is unsurpassed by that of any other 

 family of quadrupeds. 



Nearly all the various antelopes have the curious " tear-pits " 

 or " lachrymal sinuses," which are also to be seen in animals of the 

 deer family. These organs are small sacs situated below the eyes, 

 which secrete a ;^ellow waxy substance. Their use has never yet 

 been discovered. A few zoologists think these glands communicate 

 with the nostrils, and that the animals can breathe freely through 

 them during their rapid flights when alarmed. Some suppose them 

 to possess the sense of smell, and that they serve for detecting 

 noxious or poisonous plants common among the rank vegetation of 

 equatorial Africa. Others think these organs are of use when the 

 animals are drinking. Still all these opinions are purely con- 

 jectural, for their precise functions are uncertain. All that is 

 positively known about them is that the anatomy of the parts 

 demonstrates the fact that there is no communication between 

 these " tear-pits " and the nostrils or any of the other organs. 

 They are simply a sac or fold of the skin, which varies in size 

 according to the species, and can be opened or shut at the will of 

 the animal. When angered many of the animals will open these 

 glands, and others make continual use of them when any strange 

 or odoriferous substance is presented to their notice, and some 

 species appear to derive a certain amount of pleasure from rubbing 

 the inner surface against such articles. The suborbital sinuses are 

 not so general among the antelopidce as in the cervidce. 



Some varieties of this extensive family are to be found in every 

 quarter of the globe, but by far the greater number — in fact, three- 

 fourths of them — are to be found in South Africa. They are 

 therefore all peculiarly constructed for life in the sandy plains and 

 deserts. They are also swift of foot, which enables them in a short 

 space of time to travel considerable distances in case of necessity 

 and when the food supply renders this essential. Their colour also 

 as a rule harmonizes with their surroundings. 



They are the most timid of all the larger mammalia, but some 

 species are dangerous to approach when wounded or brought to 

 bay, for their sharp and long horns are powerful weapons and can 



