ENCHYTRAEIDAE 245 



The penial body (Fig. 4) is in considerable part embedded in the body-waU. It 

 consists of {a) a number of much elongated cells, vertical to the surface, forming a mass 

 looju in antero-posterior extent and 65 ju. in height; this is pierced by {b) the end of the 

 vas deferens, and {c) also by the stalks of two large glands, the "prostates"; these 

 structures are covered in by {d) a layer of muscular fibres, really the longitudinal layer 

 of the body-wall, which appears here as the fairly definite capsule of the cell mass ; 

 adding the thickness of this capsule to the height of the cells, the vertical extent of the 

 penial body is 78/x. The prostates (Fig. 4) are two on each side, one anterior and one 



Fig. 4. Marionina grisea; prostates and "penial body" (combined from several sections); x 220. ep. surface 

 epithelium ; gl. glandular cells of the rudimentary penial body ; l.tn. longitudinal muscular layer of body- wall 

 (the circular layer is not visible here); m. muscular fibres filling up angle between stalk of prostate and surface 

 layers, and covering in gland cells of penial body;/), peritoneal cells; pr. "prostate"; st. stalk of prostate; 

 v.d. vas deferens. 



posterior ; each is a conspicuous, somewhat flattened mass (flattened from above down- 

 wards) of spongy-looking gland cells, 200 ij. in antero-posterior and 240^ in transverse 

 measurement ; the glands thus take up a good part of 

 the width of the segment. Each has a stalk composed 

 of the aggregated thread-like prolongations of the cells ; 

 the stalks converge in the penial body, and eventually 

 reach the surface close to the opening of the vas 

 deferens. 



The spermathecal apparatus (Fig. 5) consists of 

 ampulla, duct, and glands, the duct being the largest 

 portion of the whole. The ampulla is only slightly 

 swollen {ca. 74/x in diameter), in the main tubular, 

 about 120/X long; it is lined by cubical epithelium, and 

 communicates by a narrow but patent passage with the 

 oesophagus. The duct is bulbous or subspherical in 

 shape, with a diameter of iio/:i and a height of about 

 i20|ti ; its lumen is narrow, and lined by elongated cells 

 with nuclei at their bases ; a muscular coat envelopes 

 the bulb, and the heads of spermatozoa pointing down- 



Fig. 5. Marionina grisea; sperma- 

 theca, in section, diagrammatic, a. 

 ampulla ; d. the bulbous duct ; gl. gland 

 mass; m. muscular layer of duct; oe. 

 oesophagus. Spermatozoa are seen in 

 the lumen, their heads in the con- 

 striction between ampulla and duct, 

 their tails pointing upwards. 



