328 OSWALD S. LOWSLEY 



In the mucosa at about the middle of the trigonum vesicae are 

 found nine very delicately constructed tubules which are recog- 

 nized as the subtrigonal glands. Most of them are simple tubules 

 that extend down to the muscle but a few of them have one or 

 two very small branches and these extend for a short distance 

 into the musculature of the bladder wall. The blind ends of 

 these tubules are a little closer to the base of the trigone than 

 the mouths of their tubules. 



Commencing at about the middle of the vesical sphincter and 

 extending down to its lower border there are found on the floor of 

 the orifice the tubules forming the glands of Albarran. There are 

 nineteen of these structures in this series, most of which are simple 

 tubular glands lined with very small columnar epithelium and do 

 not extend very far beneath the mucosa. In a few cases there are 

 several branches springing from a tubule and these in many in- 

 stances extend a short distance into the musculature of the sphinc- 

 ter. None of these tubules are found in the ventral mucosa of the 

 orifice but there are some very small evaginations in that region 

 which may later develop into tubules of the same sort. The 

 blood vessels in the mucosa of this region are quite numerous and 

 large. The tubules of Albarran's group are not surrounded by 

 any differentiated tissue as are the tubules of the prostate but 

 seem to be merely imbedded in the submucous structures. They 

 open for the most part near the middle line on the floor of the ure- 

 thra but a few open in the angular depressions at the sides of the 

 urethra which marks the beginning of the prostatic furrows. 



The middle lobe tubules have extended up behind the sphincter 

 to its uppermost border. The end of the tubule that has extended 

 the highest is situated in the middle line just above the ampulla 

 of the vas and its branches are surrounded by rather dense mus- 

 cular tissue. The whole mass lies imbedded in the loose connec- 

 tive tissue beneath the bladder musculature. Lower down in the 

 series these branches are reinforced by others of a like nature and 

 a very short distance below become connected with the muscula- 

 ture surrounding the urethra. The tissues which envelop the 

 middle lobe tubules are thicker in this specimen than in any of 

 the younger ones observed being in places as dense as the walls 



