666 PROCEEDINGS OF THE ACADEMY OF [Dec, 



and veutral to the lilue tracts. The red -staining cells in this 

 region and in the preceding glandular zone are of the coarse granu- 

 lar variety. 



After the beginning of the middle intestine and its pouches, the 

 l)lue-staining cells are no longer present, except at the most poste- 

 rior end of the body. The four tracts of red-staining cells, how- 

 ever, continue along the entire length of the intestine. Owing to 

 the increased size of the intestinal cieca and the gonads, the body 

 wall is stretched and the muscular layers are thin, so that the red 

 gland cells can reach down only a short distance, and are conse- 

 quently short, often appearing more like epithelial cells. 



At the extreme posterior end of the body both red and blue 

 cells are present in great numbers all around the body. The red 

 cells are the more abundant, and are considerably larger than the 

 blue (see fig. 15). Both fine and coarse varieties occur. 



There is no cutis in the caudicle, so that cutis gland cells are 

 necessarily absent. 



c. The Body Musculature. — The entire region of the head in 

 front of the brain, Plate XLI, fig, 18, from the epithelium, Ep., in 

 to the rhynchodseum, Rd., is made up of longitudinal muscle fibres, 

 L.M., with interlacing radial muscle fibres, r.m.J. Except for the 

 cerebral nerves, C.N., and the cutis gland cells, Cu.Gl.2, and 

 probably some very fine blood lacunse, no other organs are present. 

 The wall of the rhynchodieum, which will be described under that 

 heading, contains four stout bundles of longitudinal muscle, Ed. 31. 



Just anterior to the attachment of the proboscis to the body 

 wall, the inner ends of the radial fibres interlace more 

 closely about the rhyuchodreum, until a ring of circular muscle, 

 fig. 18, CM., is formed, which becomes the circular mus- 

 cle of the proboscis sheath. Behind the attachment of the 

 proboscis, fig. 19, y., the outermost circular fibres separate off 

 from the rest, thus forming the circular muscle of the body 

 wall, fig. 19, CM., outside the proboscis sheath. The longitu- 

 dinal fibres lying between, fig. 20, i.L.M., represent the be- 

 ginning of the inner longitudinal muscle. 



Both dorsal and ventral brain lobes, fig. 19, D.L. and V.L., lie 

 outside the circular muscle, CM., in the outer longitudinal layer; 

 but the cerebral organs, fig. 21, C Org., which are directly behind 

 the dorsal lobes and receive their nerve supply from them, lie within 



