DISEASES OF THE GENERATIVE ORGANS. 173 
retained within the abdomen; (6) inflammation of the testicles, re- 
sulting in induration; (c) fatty degeneration of the testicles, in stal- 
lions liberally fed on starchy feed and not sufficiently exercised; (d) 
fatty degeneration of the excretory ducts of the testicles (vasa defe- 
rentia) ; (e) inflammation or ulceration of these ducts; (/) inflam- 
mation or ulceration of the mucous membrane covering the penis; 
(g) injuries to the penis from blows (often causing paralysis) ; (1) 
warty growths on the end of the penis; (¢) tumors of other kinds 
(largely pigmentary), affecting the testicles or penis; (7) nervous 
‘liseases which abolish the sexual appetite or that control the muscles 
which are essential to the act of coition; (4%) azoturia with resulting 
weakness or paralysis of the muscles of the loins or the front of the 
thigh (above the stifle); (2) ossification (anchylosis) of the joints 
of the back or loins, which render the animal unable to rear or 
mount; (m) spavins, ringbones, or other painful affections of the 
lind limbs, the pain of which in mounting causes the animal to sur- 
denly stop short in the act. In the first three of these only (a, 3, 
and ¢) is there real sterility in the sense of the nondevelopment or 
imperfect development. of the male vivifying element (spermatozoa). 
in the other examples the secretion may be imperfect in kind and 
‘amount, but-as copulation is prevented it can not reach and impreg- 
nate the ovum. 
In the mare ‘barrenness is equally due to a variety of causes. In 
a number of breeding studs the proportion of sterile mares has 
varied from 20 to 40 per cent. It may be due to: (a) Imperfect 
development of the ovary and nonmaturation of ova; (0b) cystic 
or other tumors of the ovary; (c) fatty degeneration of the ovary 
in very obese, pampered mares; (d) fatty degeneration of the excre- 
tory tubes of the ovaries (Fallopian tubes) ; (¢) catarrh of the womh, 
with mucopurulent discharge; (/) irritable condition of the womb, 
with profuse secretion, straining, and ejection of the semen; (g) 
nervous irritability, leading to the same expulsion of the male ele- 
ment; (#) high condition (plethora), with profuse secretion and 
excitement; (¢) low condition, with imperfect maturation of the 
ova and lack of sexual desire; (j) poor feeding, overwork, and 
chronic debilitating diseases, as leading to the condition just named; 
(%) closure of the neck of the womb, temporarily by spasm or per- 
manently by inflammation and induration; (7) closure of the en- 
trance to the vagina through imperforate hymen, a rare, though not 
unknown, condition in the mare; (m) acquired indisposition to breed, 
seen in old, hard-worked mares which are first put to the stallion 
when aged; (n) change of climate has repeatedly been followed by 
barrenness; (0) hybridity, which in male and female alike usually 
entails sterility. 
