264 SPECIAL HISTOLOGY. 



so that here the increase of the walls may be directly de- 

 monstrated ('Zeitsch. f. wiss. Zool./ I, 84).] 



§ 208. 



Vagina and external sexual parts. The walls of the vagina, 

 1'" thick, consist of an external fibrous coat, a middle muscular 

 layer, and a mucous membrane. The thin white fibrous coat 

 presents externally a more lax, towards the interior a more 

 dense connective tissue, with numerous elastic fibres and venous 

 plexuses, and passes, without any .line of demarcation, into the 

 second, redder layer, which, together with connective tissue and 

 numerous veins, contains, particularly during pregnancy, a 

 good many, developed, smooth muscular fibres, which, witli their 

 transverse and longitudinal bundles of fibre-cells, 0*04, 0'08"' 

 long, constitute a true muscular membrane. The mucous 

 membrane is of a pale red colour, with numerous larger and 

 smaller folds and elevations — the columnce rugosa; it is com- 

 posed of a dense connective tissue, without glands, and contain- 

 ing elastic elements in extreme abundance, to which its great 

 firmness and extensibility are due. Its inner surface presents 

 numerous conical or filiform papillae, from 0*06 to 0'08'" 

 in length, and 0-025 to 0*03'" in breadth, which are entirely 

 imbedded in a tesselated epithelium, 007 — 0'09"' thick, of the 

 same kind as that in the oesophagus, the uppermost scales of 

 which, having a diameter of 0-01 — 001 5"', contain nuclei of 

 O'OOS'". The hymen is a duplicature of the mucous membrane 

 of the vagina, and contains the same elements. 



From the vagina the mucous membrane is also continued 

 upon the external genitals, invests the glans clitoridis and the 

 vestibule, with the orifice of the urethra; folds of it constituting 

 the preputium clitoridis and labia minora. On the labia 

 majora, it is continuous uninterruptedly with the external 

 integument, which, on their inner side, and at the com- 

 missura labiorum, still bears a close resemblance to a mucous 

 membrane ; whilst on their border and outer surface, and on 

 the mons veneris, it resembles the cutis in all respects. The 

 matrix of the mucous membrane of the external genital organs, 

 is a spongy, highly vascular, fatless connective tissue, con- 

 taining, however, a good many elastic fibres, and which, in its 

 condensed external layer, \ — |'? thick, corresponding to the 



