16 



the two lateral lobes. Within the body the vagina extends 

 posteriorly an equal distance (about 0.4 mm.) before opening 

 into the uterus; uterus simple, extending posteriorly (2 mm. 

 in length in the specimen measured), and showing one, two, 

 or three cyst-like dilatations in its course. The dilatations 

 mentioned are variable in size as well as in number, but may 

 reach above 0.2 mm. in width and 0.5 mm. in length. While 

 in the non-dilated parts of the uterine canal (diameter about 

 0.05 mm.) the wall is thick, rather opaque, granular, and 

 yellowish, and closely crowded with cells, the walls of these 

 cyst-like expansions are very thin, transparent, without 

 appreciable color, and made up of large flat cells very like 

 the endothelial cells of mammals. At its posterior extremity 

 the uterine tube narrows to a blunt point, into which the two 

 ovarian tubes enter. The latter are to be seen passing for- 

 ward from this point, tortuously plicated along the posterior 

 two-thirds or three-fourths of the uterus, then leaving the 

 uterus to extend forward along the body wall ventrally and 

 dorsally nearly to the level of the vaginal protrusion, and 

 ending in a large geniculate ovarian tube apparently attached 

 to the body wall. No trace of ova or of larval worms were 

 met in any of the specimens (all examined closely for this 

 feature). 



At first the peculiar protrusion of the vaginal tube was 

 supposed to be the result of artefact, but careful study soon 

 satisfied the writer that it constituted a constant and specific 

 feature; and no suggestion of similarity to allantonema 

 could be entertained. Tentatively the name Oxyuris evaginata 

 was applied in the records to the specimens, but subsequent 

 examination of the literature has fixed the prior recognition 

 of the worm to Linst'ow, and compelled the retraction of the 

 writer's provisional name and the adoption of that employed 

 by Linstow. The singularity that in both Linstow's material 

 and that of the writer only female specimens were encountered 

 is striking; and it is possible that the virgin state of the speci- 

 mens may have some bearing, as yet unappreciated by the 

 writer, upon the peculiar vaginal evolution. 



