346 OSWALD S. LOWSLEY 



the axis of the urethra for some distance. They open into the 

 urethra on the sides of the verum montanum, their mouths being 

 composed of a collapsible fold of tissue so that pressure within 

 the prostatic urethra very effectively closes them. 



8. The fused Mlillerian ducts may persist intact until the thir- 

 teenth week, after which time the lower end (utriculus prostaticus) 

 which has become quite large in size and surrounded by a rather 

 dense layer of stroma cells, contracts until after the twenty-second 

 week when it is found only in the tip of the verum montanum and 

 is relatively very small in size. It usually opens in the midline 

 just below the ejaculatory duct openings and rarely if ever is 

 there an ejaculatory duct or a prostatic tubule opening into it. 



Description of a wax model of prostate of a new-born infant 



The sections from which this model was constructed were cut 

 30 micromillimeters in thickness. Every fifth section was mag- 

 nified twenty times and drawn by means of the projection appa- 

 ratus in use at the Anatomical Laboratory of the Johns Hopkins 

 University. These drawings were traced upon wax plates 3 mm. 

 in thickness, the tubules and their branches first being identified 

 microscopically with great accuracy. The wax plates were then 

 cut in such a way that the bladder lumen and those of the pros- 

 tatic tubules were left with bridges of wax between to preserve the 

 exact contour. The wax plates were then piled, the axis of the 

 bladder and urethral lumen and the lumen of the ejaculatory 

 ducts being used as points upon which to build. The prostatic 

 tubules are represented with their branches grouped, it being 

 obviously impossible to represent every branch of each tubule. 

 The various parts of the model are held together by means of 

 pins and copper wire so that the exact position of the various 

 structures represented is maintained. The various parts of the 

 model are painted with several coats of different colored enamel 

 to make clearer the different structures reproduced. 



In conclusion I wish to express my thanks to Drs. Clark, 

 Mall and Young for many suggestions which were of great value 

 to me in this investigation. 



