THE DEVELOPMENT OF THE HUMAN PROSTATE 

 GLAND WITH REFERENCE TO THE DEVELOP- 

 MENT OF OTHER STRUCTURES AT THE NECK 

 OF THE URINARY BLADDER 



OSWALD S. LOWSLEY 



From the Anatomical Laboratory, Johns Hopkins University 



ELEVEN FIGURES (THREE COLOR PLATES) 



A review of the literature on the embryology of the prostate 

 gland and other structures at the neck of the human bladder 

 discloses a great diversity of findings. Much has been written 

 about the middle lobe of the prostate and there seem to be two 

 views very firmly held with regard to its development, one best 

 expressed by Griffiths and utilized by Tandler and Zuckerkandl 1 

 to the effect that the middle lobe is an independent structure 

 which may sometimes be lacking; the other supported by Pallin, 

 Jores and others who believe that the middle lobe is always formed 

 by ingrowths from the lateral lobes. 



Griffiths 2 concludes from his studies: (1) That the middle lobe 

 may be either present or absent at the time of puberty and in 

 adult life before enlargement takes place. (2) That this lobe is 

 independent, having glands of its own which open on parts of the 

 hinder wall of the prostatic urethra. (3) That this region devel- 

 ops separately from the part of the urethra just mentioned in the 

 same way as the lateral lobes do from the part of the urethra on 

 each side of the verum montanum, and it is not the result of an 

 extension back of gland tissue from the lateral lobes into the inter- 

 val between the vasa deferentia beneath the neck of the bladder. 



1 Tandler and Zuckerhandl, Folia Urologica, Bd. 5, 1911, p. 587, in their discussion 

 of prostatic hypertrophy state that the middle lobe is anatomically constant and 

 believe that it is morphologically and embryologically independent. 



2 Griffiths. Jour of Anatomy and Physiology, vol. 23, p. 374, 1889. 



299 



