456 THOS. H. MONTGOMERY jr., 
sperm cells, and that this process proceeds from the posterior towards 
the anterior end. 
VEJDOVSKŸ is the only one to speak of a chitinous spiculum in 
the cloaca; but with von Lınstow I agree that what he observed 
was probably a mass of glandular secretion from the wall of the cloaca. 
None of the writers have described spermatozoa of elongate form, 
such as those of Paragordius. 
XII. Parasites. 
Imbedded within the epithelium of the cuticular portion of the 
cloaca of two individuals were found certain parasites which are prob- 
ably Coccidia. The following conditions of these parasites were 
noticed. 1) A rounded or oval cell (Figs. 58, 59, Pl. 40) with a di- 
stinctly granular cytoplasm (fixation by 4°/, formalin) and very delicate 
cell membrane, containing one nucleus (N); the latter nearly spherical 
with a thick membrane, and containing a smaller body with a few 
deep-colored spherules imbedded in it. These were found in the 
cloacal cells of a worm double-stained with haematoxylin and eosin, 
yet the substance of the parasites were not colored by either of these 
Stains, the cytoplasmic granules appearing brownish-yellow, the nuclear 
membrane deep brown and the spherules of the nucleus rather dark 
and refractive. 2) Conditions more frequent than the preceding, where 
numerous refractive rods, lumps and threads occupy the greater part 
of the cell, a small portion of unchanged protoplasm being left at 
points of the periphery (Fig. 57). The irregular bodies within the 
cell were brown in color, and were not affected by the double stain. 
3) Small rounded and ovoid bodies (Fig. 56) found in the epithelial 
cells, of the same consistency and color as the bodies found within 
the cell in the 2nd condition. Perhaps these three conditions represent 
successive stages in a sporogony, the small rounded bodies in the 
epithelial cells of the host being then the spores. It is remarkable 
that no portions of these cells take on the chromatin stain. 
In one of the individuals thus infected there were found also in 
the medio-ventral body cavity, most abundantly near the posterior end 
of the latter but also scattered along its whole extent, numbers of 
small floating cells. These are mononucleated rounded cells (Fig. 60), 
the nuclei (N) situated at the surface of the cell body. These nuclei 
are very variable in shape, sometimes Ushaped, sometimes irregularly 
lobed, sometimes nearly circular in outline; sometimes the nucleus is 
