URINARY SYSTEM. 279 



terspersed with vessels and nerves, soft and uniform in its tex- 

 ture, and constituting full two-thirds of its whole ; and, in the 

 middle, a longitudinal whitish part, which, though of a very 

 loose texture, is evidently not a vacuity ; for, after some yellowish 

 fluid it commonly contains is expressed, there still remains some 

 internal cellular structure. The fluid expressible from this part 

 is said to vary in its appearance and quantity with the time of 

 life: in the foetus it is said to be red and abundant; yellowish 

 and sparing in the adult ; yellower still and more scanty as age 

 advances. This body receives two or three small vessels, either 

 from the emulgent artery or the aorta, or from both ; and these 

 have their full proportion of veins. It has also an adequate 

 supply of nerves coming principally from the renal plexus. 

 What the disposition or arrangement of these several component 

 parts may be, remains yet to be developed. M. Girard says, 

 concerning them, that, although these bodies are plentifully 

 furnished with bloodvessels and nerves, " ils n'offrent dans leur 

 organisation aucune disposition qui puisse faire presumer une 

 secretion particuliere." 



The physiology of the capsulae renales remains to this day an 

 unsolved problem. Not one fact has been broached to lead to 

 any rational hypothesis. All that Mailer's indefatigable research 

 and penetrating mind could discover for certain about them, 

 was, that they secrete a fluid more required in foetal than adult 

 life, and that their functions are probably important since they 

 are found in so many animals. 



OF THE BLADDER. 



The musculo-membranous bag that receives the urine from 

 the ureters. 



Situation. — The bladder occupies the middle and inferior 

 regions of the pelvis, taking the oblique axis of that cavity, and 

 resting upon the symphysis pubis, with the rectum above it in 

 the male, the vagina in the female. In the undistended state, 

 this viscus is wholly confined to the pelvic cavity ; but when 

 full, its fundus advances before the pubes into the abdomen, the 

 advancement being in ratio with the degree of distention : in 

 the foetus it rises still more into the abdominal cavity, as a ne- 

 cessaiy consequence of its proportionally greater development, 

 as well as of the narrowness and shallowness of the pelvis at 

 that period. 



Figure. — In a state of distention the bladder is pretty regu- 

 larly pyriform, and its parietes are thin and semi-transparent; 

 but when completely empty, it assumes the spheroid figure, be- 



