244 NORMAL HISTOLOGY. 



tozoa. The "sperm crystals," formed in semen on standing and attributed 

 to the products of the prostate, are not found in the prostatic secretion during 

 life, although frequently present in the gland after death. 



The blood-vessels supplying the prostate enter the periphery of the 

 gland at various points, particularly in company with the ejaculatory ducts. 

 The interlobular twigs follow the septa and eventually break up into capillary 

 networks that surround the alveoli. The numerous venous radicles form 

 close meshworks within the grandular tissue and around the ducts. The 

 larger veins leave the deeper parts of the organ on each side and unite into a 

 plexus within the capsule, from which pass emergent trunks. 



The lymphatics arise in lymph-channels around the alveoli. From 

 the deeper networks stems pass to the surface, where they form a second 

 and superficial network from which efferents course in various directions. 



The nerves of the prostate are chiefly sympathetic fibres derived from 

 the hypogastric plexus, numerous microscopic ganglia occurring along their 

 course. Their ultimate distribution is largely to the walls of the blood- 

 vessels and to the unstriped muscle, additional fibres being traceable into 

 the glandular tissue, outside the basement membrane of the alveoli. Sen- 

 sory endings include special terminations in the form of lamellated corpuscles, 

 end-bulbs, and peculiar encapsulated endings, which are modifications of the 

 Pacinian and Krause corpuscles. These peculiar end-organs are found 

 chiefly within the fibrous capsule. 



THE BULBO-URETHRAL GLANDS. 



The bulbo-urethral or Cowper' s glands are two small bodies situated on 

 the under surface of the membranous portion of the male urethra, one on 

 either side of and close to the mid-line. In general form and size (58 mm. 

 in diameter) they resemble a pea, although their contour is irregular. 



The ducts of the glands, about 1.5 mm. in diameter and from 3-4 cm. 

 in length, run forwards and medially and open by small slit-like orifices, 

 often by a common opening, on the lower wall of the bulbus part of the 

 spongy urethra. The glands are mucous tubo-alveolar in type, their ter- 

 minal divisions ending, after more or less branching, in irregularly sacculated 

 compartments. In places the latter communicate by means of a reticulum 

 of connecting canals. The alveoli are lined with low columnar or pyriform 

 cells, among which mucus-secreting elements are plentiful. The cuboidal 

 epithelium that lines the smaller ducts, as well as the dilatations connected 

 with them, is succeeded by columnar cells within the larger ducts until near 

 their termination, where the simple epithelium is replaced by two or more 

 rows of cells. The divisions of the gland are united by intertubular con- 

 nective tissue and invested by a fibrous envelope containing a considerable 

 quantity of unstriped muscle intermingled with striated fibres derived from 

 the surrounding compressor urethrae muscle. The secretion of Cowper' s 

 glands is clear and viscid and of alkaline reaction. 



The blood-vessels supplying the bulbo-urethral glands, branches 

 from the arteries of the bulb, form capillaries that enclose the alveoli and 

 diverticula. The veins begin in the interalveolar tissue and are tributary to 

 those from the bulbus part of the spongy body. The lymphatics arise 

 from networks of lymph-channels in the interalveolar connective tissue and 

 join into efferents to the internal iliac lymph-nodes. The nerves are from 

 the pudic and include both medullated and nonmedullated fibres, the latter 

 being principally from the sympathetic. 



