MAMMALIA. 657 



a) With lachrymal sinuses notie. 



Sp. Ovis tragelaphus Cuv., SCHBEB. Sduyth. Tab. 288 B ; ruddy, the horns 

 thick at the base, bent outwards with the point in some degree curved 

 downwards ; long hair at the neck and fore legs, in North Africa. 



b) With lachrymal sinuses distinct. 



Sp. Ovis Aries L., SCHREB. Saugth. Tab. 289 294 c ; the sheep, with the 

 tail usually longer than in any of the wild species. This annual is one of 

 the most useful which man has subjected to himself 1 . Since it was origi- 

 nally an inhabitant of mountains, it thrives better in high and dry regions. 

 It is subject to many diseases, amongst which the so-named foot-rot may be 

 mentioned ; under which appellation, however, very different maladies have 

 been confounded. Frequently there arises a lameness of the feet 2 , that to 

 which we allude, from the suppression of a secretion formed by the seba- 

 ceous glands of a sacculated inversion of the skin, which opens in front 

 between and above the hoofs of the fore and hind feet, and the consequent 

 swelling of the apparatus. This dermal sac is found in some other rumi- 

 nants, but in the hind feet alone. See A. BONN Verhandel. der Eerste 

 Klasse der Koninkl. Nederl. Instituut, Amsterdam, 1820, v. bL 125 155, 

 F. KLEIN Diss. inaug. de sinu cutaneo ungularum Ovis et Caprece, cum 

 tab. Berolini, 1830, 8vo; E. ROUSSEAU, GUEB. Revue et Magasin de 

 Zoologie, 1852, pp. 510 516, PL 21. 



Sheep begin to change their teeth in their first year ; when three years 

 old they have got all their permanent teeth, except the two outer incisors, 

 which appear in the fourth year. The ram is fit for procreation when 

 eighteen months old ; the ewe can copulate when one year old ; the period 

 of gestation is about five months, the produce one or two lambs. The 

 rams are mostly horned ; sometimes the ewe also has horns, which however 

 are smaller and less twisted. There are many varieties of the sheep, 

 amongst which the merino- sheep (varietas hispanica) deserves mention on 

 account of its fine wool, the Astracan sheep for the curly fleece of the 

 lambs, and the Iceland sheep (varietas polycerata} for its four or six horns. 

 In some the tail is peculiarly broad and fat; others are distinguished by 

 large deposits of fat on the croup (car. steotopyga PALL.). 



In the wild species the tail is very short. To these belongs Ovis Ammon 

 (L., in part) Cuv., Ovis argali PALL. Spic. Zool. xi. Tab. i ; the Argali 

 sheep. Of this species both sexes have horns, which in the female are 

 smaller and at their base are set longitudinally on the skull (not with the 

 broader surface transverse, as is usual in the sheep), in the male particu- 

 larly thick and large. That our domestic sheep is derived from this species 

 is scarcely probable ; compare TILESIDS, who defends this derivation, and 

 BOJANUS, who advances objections to it from difference in the skull, 

 in Act. Acad. Leop. Carol, xii. i, p. 279, pp. 291 300. Other writers 



1 Although " Pecus" is applied by the ancients to denote all kinds of cattle, 

 it refers especially, when no other name is added, to sheep. See PLINIUS Lib. vm. 

 cap. 47. 



2 " Turpis podagra," VIRGIL. Georg. m. 299. 



VOL. ii. 42 



