340 



OSWALD S. LOWSLEY 



In most descriptions of the prostatic urethra it is stated that 

 there are from twenty to thirty duct openings upon its floor. My 

 studies have convinced me that this number is far too low. The 

 results of microscopic studies of the number of tubules composing 

 the prostate have been arranged in the form of a table. 



TABLE 2 



Showing number of tubules of each lobe opening into prostatic urethra, the number of 

 Albarran' s tubules, and the number of subtrigonal tubules. 



SIZE OF FETUS 

 CROWN-HUMP 



MEASURE- 

 MENT 



cm. 



7.5. 



12.5. 

 19... 

 27... 

 36... 



MIDDLE 

 LOBE 



LATERAL 

 LOBES 



Averages 11 



12 

 7 



10 

 



11 

 9 



10 



39 

 27 

 46 

 42 

 36 

 34 



POSTERIOR ' ANTERIOR 

 •LOBE LOBE 



TOTAL NO. 

 OF PROSTA- 

 TIC TUBULES 



11 



6 



4 

 10 



9 

 11 



12 

 13 



14 



37 



74 

 53 

 74 

 59 

 64 

 56 



SUBCERVI- 

 CAL GLANDS 

 OP ALBAR- 

 RAN 



9 



63 





 

 8 



11 

 9 



19 



SUBTRIGONAL 

 GLANDS 



12 



* The averages are taken from the specimens in which the structure is present 

 in case of middle lobe and the groups of Albarran and the subtrigonal group. 



By referring to table 2 it is seen that in no case were there fewer 

 than fifty-three prostatic ducts opening into the urethra, and in 

 two specimens there were as many as seventy-four, the average 

 for six specimens studied microscopically in series being sixty- 

 three, including one specimen in which the middle lobe was en- 

 tirely lacking. The number of middle lobe tubules vary from 

 seven to twelve, the average in five prostates being ten. The 

 lateral lobe tubules vary in number from twenty-seven to forty- 

 six, the average in six specimens being thirty-seven. The pos- 

 terior lobes show a variation of from four to eleven, eight being 

 the average number of tubules in the six specimens recorded. 

 The anterior lobes present a very interesting variation. It is 

 seen that up until and including the sixteenth week the tubules 

 composing the anterior lobe are quite large and numerous, but 

 after that time there is a decided decrease in the number, and, as 

 has already been stated, the size and branches of the individual 



