430 SUMMARY OF CURRENT RESEARCHES RELATING TO 



all. It is suspended to the top of the vestibule by a thickened band 

 formed by this outer connective tissue. 



The wall of the multifid glands is made up of muscular, chiefly 

 horizontal, fibres and of connective-tissue fibres ; the true gland-cells 

 form a lining mosaic ; they are cylindrical, cup-shaped epithelial cells, 

 becoming purely cylindrical at the commencement of the excretory 

 tube : the substance secreted by the glands is remarkably refractive 

 and dissolves in acetic acid. The vagina exhibits in transverse section 

 the same structure as the penis ; the connective-tissue layer may either 

 become continuous with the connective reticulum of tlie copulatory 

 sac or form an independent zone, in any case lying just beneath 

 the epithelium. The copulatori/ sac consists of a bulb prolonged into 

 a filiform tube ending in an ampulla ; the external wall of the bulb is 

 muscular and consists of circular fibres immediately underlying the 

 epithelium and of more numerous transverse converging ones, which 

 unite with the former and with the connective fibres to form a dense 

 reticulum ; the villous interior of the bulb is lined witli epithelium 

 0-05 mm. thick, which disappears in the ampulla. The latter organ 

 is generally found partially filled with a concentrically stratified, 

 nucleated substance, which may perhaps be merely the result of 

 coagulation of the glutinous liquid which carries the spermatozoa. 



The ovispermiduct (^uterus of former aixthors) is a tube divided 

 longitudinally into a larger groove which acts as an oviduct and a 

 smaller one which transmits the sperm : the two grooves are in com- 

 munication. The latter one r<^ceives the secretioii of the tubules of a 

 gland, called the prostate, which lies along its course. The oviduct 

 proper, that is. the independent tube which leads from the common duct 

 to the vagina, varies in its characters at different points ; near the 

 joint duct it is partially divided into tvvo by a large longitudinal fold ; 

 as it approaches the vagina it becomes more like that organ ; it differs 

 from it, however, in having a set of tubular glands lying in the 

 subepithelial connective tissue ; they first appear only at the bottom 

 of the groove formed by the fold, but ultimately extend to the apex of 

 the fold and to the wall opposite to it. The lining epithelium 

 is ciliatetl, its cells range in size from 0'06 mm. in diameter near the 

 vagina to 0"03 mm. near the ovispermiduct. This organ too has 

 glands, inci'easing in number backwards at the expense of the 

 muscles, which ultimately become reduced to a few decussating fibres ; 

 the glands are conical tubes with squamous secreting epithelium, and 

 may be well studied by the use of bichromate of ammonia or by 

 hardening in alcohol or chloride of gold ; in Limax they are simple 

 caeca lined by a non-ciliated modification of the ordinary epithelium 

 of the oviduct. In Helix pomatia the cells of the ciliated epithelium 

 of the ovisjiermiduct are smaller than in Planorbis, being only 

 0- 03-0 -04 mm. long, including the cilia; their function is probably 

 merely circulatory. The prostate is a racemose gland whose follicles 

 are lined by cup-shaped epithelial elements whose nuclei are placed 

 near their bases ; the follicular cavities are small and narrow as com- 

 pared with those of Limax ; a mucous substance has been observed 

 still in contact with the secreting cells. The uterine artery, which 



