XXVIII.] 



KIDNEY. 



313 



Cylindrical 

 cells. 



Leucocyte. 



FlG. 303. V.S. Epithelium of the Mucous Membrane 

 of a Human Bladder. Muller's fluid, x 560. 



(e.) (H) The transitional epithelium, and the variation in the 

 shape of the cells arranged in several layers, from the free mucous 

 surface outwards. 



10. V.S. Bladder (fig. 

 303). (a.) (L) Most ex- 

 ternally a thin fibrous coat, 

 in some places covered by 

 a serous coat. 



(b.) The muscular coat, 

 composed of longitudinal 

 and circular smooth fibres. 

 Usually there is an outer 

 and an inner longitudinal 

 layer with a circular layer 

 between. The appearance 

 of these layers will depend 

 on the plane of the sec- 

 tion. 



The submucous and mucous (H) coats are like those of the 

 ureter. 



(c.) (H) The transitional epithelium and the great variety in the 



shape of the cells from below 



upwards. Occasionally amongst 

 the epithelial cells are leucocytes 

 (tig. 303). It is important to 

 observe that the thickness and 

 shape of the lining transitional 

 epithelium will necessarily vary 

 with the state of distension or 

 contraction of the bladder. 



11. T.S. Penis, e.g., of a 

 monkey or other small mammal. 

 Harden it in alcohol or fix in 

 Flemming's fluid. Make T.S. 

 and stain with safranin. 



(a.) (L) It consists of the two 

 corpora cavernosa, placed dor- 

 sally, one on each side of the 

 middle line, and inferiorly the 

 cor/tuft i<ixiji(jiosum. In the 

 centre of the latter is the 

 urethra as a transverse slit. 

 In the prostatic part the mucous membrane is lined by transitional 

 epithelium, but in the body of the penis it is lined by the columnar 

 variety, except at the meatus, where it is stratified. 

 28 



sum; s. Septum; it. I'lvthra : J)V. 



&V v<Jil1 ; LA ' Duml urU ' rie " : *' 



