56 THE ANATOMY OF AN AUSTRALIAN LAND PLANARIAN. 
long and strong on the ventral surface. In Geoplana traversit, however, described in 
the same article, Moseley could not detect cilia on the dorsal surface, either by direct 
observation or experiment. 
I must consider the presence of cilia on the dorsal surface of Geoplana spenceri 
asa point still requiring demonstration. It seems hardly probable that they can have 
escaped detection in my specimens, preserved as they were with the utmost care. 
Nevertheless it is possible, as observed by von Kennel (3), that their presence might 
be hidden by the numerous ejected rod-like bodies. 
I also repeated the experiments of Fritz Miller, following Moseley’s example in 
using small pieces of paper instead of arrowroot, but with no very definite results, and 
IT am inclined to think that the observed motion of particles on the dorsal surface 
may perhaps, at any rate in some cases, be accounted for by the muscular action 
of crawling, and by the natural flowing off of slime from the surface. 
5S? 
Epidermis of the Dorsal and Lateral Surfaces.—According to Moseley (6), ‘‘ the 
entire substance of the epidermis is probably made up, in the living condition, of 
cells resembling the gland-cells described, but of various dimensions, and of cells 
containing rod-like bodies.” If there existed an epidermis of this structure it would 
be a very curious fact, as no mention is made of any ordinary, nucleated cellular 
elements. Moseley, however, was evidently led astray in his conclusions by the 
unsatisfactory condition of his material. As a matter of fact, the constituents of the 
epidermis mentioned by him are no part of the epidermis proper at all, but are simply 
wanderers on their way to the surface from the deeper layers of the body. 
The epidermis on the dorsal and lateral surfaces of Geoplana spenceri is made up 
of closely packed, elongated columnar cells, each with an oval or rounded nucleus at 
its base (Fig.6). The bodies of these cells are very delicate, and they very readily shrivel 
up. Wedged in between them are found numerous other structures, which are so 
abundant as very greatly to obscure the epidermic cells, and which Professor Moseley _ 
mistook for the true epidermic structures. They are of two kinds—(A) Masses 
of mucous (Fig. 6, mu.) on their way to the surface from the deep-lying glandular cells 
(shme-glands). These masses of mucous are characterised by staining very deeply 
with borax carmine ; sometimes they appear almost homogeneous, and sometimes 
coarsely granular, but I have no doubt they are all one and the same thing. In some 
cases they are seen to be continued by narrow stalks for some distance below the 
epidermis (Fig. 10), and they are obviously blocks of mucous, hardened by the action 
of the reagents employed whilst in process of extrusion. Moseley describes and 
figures similar bodies in the forms investigated by him (6); he speaks of them as 
‘irregular elongated masses of finely granular material which stain deeply with 
carmine, and as they are often seen to be in connection with the glands beneath the 
skin, are probably masses of slime hardened by the spirit in the act of their extrusion 
