58 LHE ANATOMY OF AN AUSTRALIAN LAND PLANARIAN. 
present in Geoplana.” Von Kennel (8) describes briefly, but without figures, the 
structure of the epidermis in the German land Planarians, and recognises its true 
nature. Jijima (7), in the case of the fresh-water Tricladians, comes to much the 
same conclusions as those arrived at by von Kennel and myself in the case of the 
terrestrial forms. He observes, ‘‘ Hinzelne Driisen, wie sie Moseley beshreibt, 
sind niemals in dem Epithel vorhanden und ich muss deren Annahme mit Kennel 
fir eine durch die unvollkommene Behandlung hervorgerufene Tauschung erklaren.” 
The structure of the epidermis, as described and figured by Jima in Planaria 
polychroa, bears considerable resemblance to what occurs in Geoplana spencert. 
I would refer especially to his figures 4 and 5 (Taf. xx.), He describes and figures the 
nucleus, however, as occurring in about the middle of the cell, and von Kennel makes a 
similar observation with regard to the nucleus in the ventral epidermic cells of the 
forms examined by him, while in Geoplana spencer it occurs at the base of the cell. 
Jijima also describes the rod-like bodies as occurring within the individual cells of 
the epidermis, instead of. between them, as in Geoplana spencert. I am inclined to 
think that he must be mistaken in this respect, for it is hardly conceivable that the 
rods, which originate in deep-lying mother cells, should, after leaving the latter, 
again enter another kind of cell. Jijima’s description of the nuclei themselves, as 
roundish bodies containing a great number of strongly stained granules, agrees 
precisely with my own observations. He also notices a fact with which I have 
been repeatedly struck in the case of Geoplana, and which may be best stated in his 
own words, ‘‘ Kerne von solcher Beschaffenheit treffen wir auch in allen tibrigen 
Geweben des Kérpers mit Ausnahme der Kier und gewisser Driisenzellen.”’ 
Special Modification of the Epidermis in the Peripharyngeal Cavity.—When the 
pharynx is retracted it lies in a very definite cavity, which opens on to the ventral 
surface of the body by a minute rounded aperture, as shown in figures 8 and 9. The 
outer surface of the pharynx itself is lined by a richly ciliated epithelium, which 
is continued for a short distance all around the insertion of the pharynx, as far as 
the points marked a and c in the figures. Also, the ordinary epidermis of the ventral 
surface of the body appears to be continued for a short distance inside the opening of 
the cavity, as far as the points marked b and d in the figures. Over the remainder 
of the wall of the peripharyngeal cavity the epidermis becomes peculiarly modified to - 
form a glandular organ, which appears to have been hitherto unnoticed. The epidermic 
cells increase greatly in size and lose their cilia, and in their most highly developed 
condition they assume an inverted flask-shaped form. These flask-shaped cells are 
shown in figure 7. They lie with their narrow ends resting on a thin basement 
membrane, and their broad rounded ends directed towards the lumen of the cavity. 
Hach cell is differentiated into two tolerably distinct regions—(a) the neck, which is 
comparatively hyaline, and contains the granular nucleus; and (0) the body of the 
cell, which is coarsely granular, and stains very deeply indeed with borax carmine. 
