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‘© 2) 
The Blood Vessels of the Prostate Gland 
Branches of these envelop the surface of the gland and give off smaller 
ones, which penetrate between the lobules in the fibrous-tissue septa. 
The capillaries are separated from the epithelial cells only by a very 
thin basement membrane. 
There are superficial veins corresponding with the arteries. 
For the outer superficial fourth of the gland the return flow is towards 
the surface. ‘The inner three-fourths are drained by veins which empty 
into the venous plexus immediately around the urethra. 
The lobule is formed primarily by the individual gland ducts as shown 
in Figure 2. The main arteries surround this lobule which they pene- 
trate at many points. ‘The veins leave the lobule mainly at its peripheral 
and central (urethral) ends as shown in Fig. 1. 
EXPLANATION OF PLATES I AND II. 
Kia. 1 is from a section of a prostate gland of a dog injected with carmine 
gelatine and ultramarine-blue gelatine. The arteries in the section were 
blue, the veins and capillaries red. The section was cut free hand, about 
50” in thickness, and cleared both in glycerine and in creosote. In the 
figure this artery is red and this vein blue. Art., Arteries; Art. Col. Sem., 
Artery of the colliculus seminalis; Art. duct. ej., Artery of the ejeculatory 
duct; Col. Sem., Colliculus seminalis; V. Pl., Venous plexus around the ' 
urethra. 
Kia. 2. Lobule of prostate from a gland which had been injected with 
ultramarine-gelatine blue into the artery, and with carmine gelatine into 
the prostatic duct. Pr. duct., Opening of the prostatic duct into the urethra; 
Gl. Tis., Gland tissues distended with carmine gelatine; Art., Surrounding 
artery. In this figure the artery is represented in red and the ducts in brown. 
Fic. 38. Very thin section from the prostate gland of a dog. Capillaries in 
red, injected with carmine gelatine. Section stained with iron hematoxylin, 
with artificial yellow tinting of basement membrane. Oil immersion with 
one inch eye-piece amplification. Cap., Capillaries; B. M., Basement mem- 
brane; Gl. Ep., Glandular epithelium; Cap. L., Capillary loop. 
