64 MR. OGILBY'S MONOGRAPH 



homogeneous and undoubtedly natural ; as for instance in Ovis, where the Argali, the 

 Mufflon, and the domestic species still retain these organs, deprived indeed of all power 

 of voluntary motion, and of the secretions which accompany them in their normal 

 form, whilst they are altogether wanting in the Nahoor and Wadan (0. tragelaphus). 



IV. Feet and Digital Pores. — The organs of locomotion are the last parts of the 

 animal structure which it is necessary to consider as furnishing characters for generic 

 distinction ; yet there is less variety in the mere form of the feet among the Ruminan- 

 tia than in any other equivalent group of Mammals. With the exception of the Came- 

 lideE, all these animals have the foot formed on the same model, and differ only in some 

 slight modifications of the hoof, which is always adapted to the nature of the habitat. 

 Mountain Ruminants, for instance, such as the Goats and Capricorns, have the frog or 

 under part of the foot hollow, and the hoof surrounded by a prominent sharp rim, 

 which, by rapidly catching upon the slightest asperities, gives them a firmer hold of the 

 slippery and precipitous rocks among which they dwell ; and the effect is increased by 

 the rigid structure of the pastern and the shortness of the hoofs. The inhabitants of 

 the sandy deserts and swampy savannahs, on the contrary, have broad flat hoofs to 

 prevent them from sinking ; whilst those of the open stony plains are chiefly remarkable 

 for the length and springy elasticity of the pastern, the hoof being of an intermediate 

 form between the two extreme varieties just desci'ibed. 



These modifications, however, are scarcely definite enough to be employed in distin- 

 guishing genera ; but the glands or pores which open between the toes of many Rumi- 

 nants afford much better characters for this purpose, and bear a very evident relation 

 to the habits and geographical distribution of the animals. These glands are of greater 

 or less extent in different genera, according to the nature of the localities which they fre- 

 quent ; in the Gazelles, Antelopes, Bubals, and Oryxes, which inhabit the burning deserts 

 of Africa and Central Asia, they are extremely large, and frequently occupy the whole 

 interspace between the first and second phalanges ; in the Sheep, Capricorns, and Trage- 

 laphs, again, which live on the open grassy downs and mountains of a less arid nature, 

 they are of much smaller size; whilst in the Oxen, Calliopes, &c., which inhabit the 

 moist forests and swamps of tropical regions, or the grassy meadows of temperate cli- 

 mates, they are altogether wanting. 



The structure of these organs does not appear to differ from that of the glands already 

 described. They secrete an oily fluid, which keeps the whole foot continually moist 

 and cool, lubricates the hoof, and prevents it from cracking under the influence of a hot 

 tropical sun or parching desert wind ; and this remarkable and beautiful instance of 

 design is exemplified in many important cases. The cattle of South Africa, for instance, 

 when travelling over the great Karroo, and long exposed to the parching winds which 

 prevail there, contract a disease, familiarly called the hoof-distemper, brought on entirely 

 by lack of moisture ; the foot inflames, the hoof cracks and drops oft', and the traveller 

 is often in danger of perishing in the wilderness by the loss of his cattle. Yet the 



