GENITAL ORGANS. 307 



of the kidney, is a thin-walled tube about as thick as a goose- 

 quill. 



The hlailder (D) is a membranous sac in which the urine is 

 stored up. The pelvic cavity retains this reservoir, which may 

 extend into the abdominal cavity. The ureters open into the 

 lower portion of the bladder, which becomes constricted pos- 

 teriorly into a kind of neck. In front the sac is rounded, and 

 here may be seen a scar, the spot to which a fcetal structure, the 

 urachus, was attached. This urinary sac is united to the 

 pelvis, to the rectum, and to the vesicute seminales in tlie 

 horse, and in the mare to the uterus and vagina. From the 

 neck of the bladder arises tire urethra (K and L),, which carries 

 away the urine to the exterior. The urethra is also the duct for 

 the genital products in the male, and more or less so in the 

 female. There is thus a connection between the urinary and 

 reproductive organs. They are often spoken of unitedly as the 

 uro-genital 07yans. 



The genital organs (fig. 160) in the male consist of two 

 glands, the testicles [E) and the epididymis (e), vas deferens 

 (F), vesioulse seminales {H^, ejaculatory ducts, urethral canal, 

 prostate (/) and Cowper's glands (/), the corpus cavernosum 

 {M), and the penis (N). The testicles are abdominal in the 

 foetus, but later descend into a sac, the scrotum, lying at the 

 bottom of this sac and supported by the spermatic cord. These 

 glands, which produce the male cells or spermatozoa, are oval 

 bodies, made up of a large number of lobules, each lobule 

 being composed of two or three long tubes, seminiferous tubes, 

 often over a yard in length. Closely applied to this testis is 

 the elongated epididymis, which is made up of from twelve 

 to twenty tubes, united into one twisted tube, from which 

 springs the straight vas defei'ens, a canal as thick as a goose- 

 quill in the horse. Situated just above the bladder are two 

 oval glandular pouches (//), in which spermatozoa are stored, 

 and Avhich also add a fluid to the semen. The ejandatvrij duct 

 is short, and succeeds the narrow canal of the vesicula after the 



