330 STRUCTURE OF THE SHEEP. 



The bladder is situated partly in the pelvis and partly in 

 the abdomen, the latter part being comparatively free, whilst 

 the former is closely attached to the pelvis. The shape of 

 the bladder is too well known to need description. It be- 

 comes smaller as it approaches its posterior part, where it 

 contracts and forms the neck just prior to its opening into a 

 canal called the urethra. The bladder, although apparently 

 so thin, yet has three coats, the middle one of which is mus- 

 cular and possesses the power of contracting so as to expel 

 the whole of its contents when required, and the opening is 

 usually kept closed by a sphincter or circular muscle, which 

 relaxes when the bladder is being emptied. The urethra in 

 the ewe is very short, a few inches only in length, and it is 

 guarded by muscles which are employed both in expelling 

 the urine and in the act of procreation. 



In the ram the urethra is of considerably greater length, 

 extending the whole length of the penis ; it forms an acute 

 angle at the perineum, just under the anus. The penis is a 

 muscular organ, having a very curious structure, which ena- 

 bles it to receive at times a considerably increased quantity 

 of blood, which causes the erection of the organ and fits it 

 for the purpose of generation. Its usual state, however, is 

 flaccid, when its use is confined to the ejection of the urine. 



The vagina and uterus, or womb or lamb-bag, lies between 

 the rectum above and the bladder below, and though much 

 within the pelvis in their ordinary state, yet when pregnant 

 they rise into the abdomen to a great extent. The vagina, 

 which commences a few inches within the body, is a cylin- 



and, though less abounding m substances containing nitrogen, possesses 

 a larger proportion of salts. The following is an analysis of 100000 

 parts by weight : — 



Water 96000 



Urea, along with some albumen and coloring 



matter 2800 



Salts of potash, soda, lime, and magnesia, with 



traces of silica, alumina, iron, and manganese . 1200 



100000 

 This gives 4 per cent, more water than the urine of cows, than which it 

 is less fertilizing to the soil, if the latter is properly prepared ; but the 

 dung of sheep is much more nutritious than that of cows, and the urine 

 likewise, when dropped on pasture land, is more serviceable, in conse- 

 quence of the small quantity deposited at a time, and the less proportion 

 of caustic ammonia contained, so that it does not render the herbage 

 rank, as is the well-known effect of the fresh urine from cows. 



