188 THE SHEPHERD'S MANUAL. 



the male. A canal or duct called the 'Das deferens, leads from the 

 testes to the outward and exposed male organ. In the ram this 

 organ has at its extremity a small spiral appendage called the 

 vermiform, (or worm-like), appendage. This has a very narrow 

 orifice, and is often on this account the seat of obstructions which 

 are difficult to remove. 



The testicles of the ram are very large in proportion to its size, 

 and the whole reproductive powers are highly vigorous, enabling 

 him, when well nourished, to serve effectively a hundred ewes in 

 a season. 



OBSERVATIONS ON THE DISEASES OF THE SHEEP. 



In judging of the symptoms of disease in the sheep, it is neces- 

 sary to take into account the nature, constitution, and habits of 

 this animal. The diseases of the sheep are numerous and more 

 generally fatal than those of other domestic animals. The diges- 

 tive organs of the sheep are largely and powerfully developed, and 

 its capacity for the production of blood is very great. Yet its 

 needs for this large supply of blood is not to support its nervous 

 system, which is feebly developed, nor its muscular exertion, of 

 which it is incapable to any great extent, nor its circulation, which 

 is onty of inferior amount, but the surplus must necessarily go to 

 the production of flesh, fat, and wool. In the sheep, therefore, 

 the production of flesh, fat, and wool, is the chief of its functions, 

 and the greater part of its vitality is expended in this way, leaving 

 but a small amount to sustain the comparatively weak vascular 

 system. The sheep is unable to sustain severe muscular labor ; and 

 slow movement, except for very limited periods, is all that it is 

 capable of. From the small brain development of the sheep, its 

 weak nervous and circulating system, it is to a great extent free from 

 diseases of an inflammatory character. From the large exercise 

 of its digestive powers, it is to be expected that diseases of the di- 

 gestive organs should be frequent and serious, and this we find 

 to be the case. From the same causes that render it compara- 

 tively free from diseases of an irritating character, it with more 

 than usual readiness succumbs to those in which debility and the 

 exhaustive effects of parasites are the chief features. Indeed it is 

 to the attacks of parasites, both external and internal, that sheep 

 owe their most troublesome and fatal disorders. Infectious or 

 contagious diseases have greater scope for action amongst sheep 

 than amongst other domestic animals, by reason of their gathering 

 together in large flocks, and thus being more exposed to unwhole- 



