THE ANATOMY OF AMPHIPTYCHES URNA. 149 
Fig. 7.—Portion of a transverse section in the region of the receptaculum at its 
anterior end. On the upper side is the central space containing densely packed and 
clearly nucleated cells—the ova—which here take the stain (borax carmine) more 
deeply and uniformly than in the scattered ovaries ; ct. connective tissue forming 
the ‘‘ ground substance” of the body; ov.' ova; yrs.receptaculum; x. problematic 
nucleated cells amongst the spermatozoa, and which are perhaps to be regarded as 
sperm-blastophores. Drawn under Zeiss F. oc. 2. 
Fig. 8.—Transverse section across an excretory canal. cut. the definite 
cuticular-like lining absent at one point where cilia (c) project into the lumen. A 
longitudinal row of these cilia project into the canal. The cilia are apparently 
connected with cells, as nuclei can be distinguished at the base of the row, but not 
the definite outlines of cells. The cilia are massed so as to form the curious flame- 
shaped structure represented in the diagram; c. cilia; e. lumen of canal; nw. nuclei 
in the connective tissue surrounding the canal. Drawn under Zeiss F. oc. 2. 
Fig. 9.—Section across one of the folds of the rosette at the anterior end of the 
body. The outer surface lies to the left hand. Both outer and inner surfaces are 
covered with a definite cuticle ; but whilst the epidermic cells on the outer surface 
are of the ordinary columnar form, those of the inner surface have become largely 
transformed into distinct glandular cells, considerably shorter than the ordinary 
columnar ones, and taking stain deeply. Between the two layers lie the muscle 
layers and the central mass of connective tissue, which is permeated with a network 
of very fine tubules, non-ciliated, and connected with the excretory system. ct. 
connective tissue; cut. cuticle; e. excretory vessels; ep. epidermic cells of the outer 
surface; gc. gland cells on the inner surface; mu. muscle fibres. Drawn under 
Zeiss F'. oc. 2. 
Pratt 13. 
Fig. 1.—Diagrammatic representation of the network of excretory vessels. The 
reproductive organs are indicated in outline, and in the central part of the body 
occupied by the uterus the network is much more open than in the lateral regions. 
f.o. opening of female organs; m.o. opening of male organs; 2. lateral nerve 
cord ; ne. ring of excretory vessels just below the proboscis ; ne. 0. external opening 
of the excretory organs; fp. proboscis; sp. duct of spermatheca; sp. 0. opening of 
spermatheca ; ut. uterus. 
Fig. 2.—Section through a small portion of the uterus of a specimen containing 
ova in an early stage of development, and in which ova are still passing into the 
uterus. In the lumen of the tube are seen many nucleated cells, some of which will 
form, probably, ova, and others food yelk, and amongst these a yellowish material, 
