142 
ME. H. 1ST. MOSELEY ON THE ANATOMY AND 
in carmine preparations, from the fact that it remains almost unstained. The glandular 
elements are transparent and devoid of nuclei ; at the mouths of the follicles they are 
long and tumid, and form finger-like processes, whilst in the cavities of the follicle they 
are smaller and angular in outline from mutual appressure. 
In longitudinal sections of the bulb of the penis there are to he seen running inwards 
from its periphery to its glandular cavity peculiar wavy bands, which in carmine prepara- 
tions stand out into relief unstained amongst the surrounding deeply stained muscular 
tissue (Plate XIII. fig. 2, u ). Similar structures are to be seen running down the penis 
longitudinally (Plate XIII. fig. 1, u), at pretty regular intervals from one another. 
When these wavy bands are seen in section, they appear as spaces filled with a fine areolar 
network, like that exhibited by the primitive vascular system (Plate XIV. fig. 6). I once 
held that these bands represented a series of tubular canals in connexion with the primi- 
tive vascular space, and serving for distending and erecting the penis, in the same manner 
as, according to Keferstein’s conjecture, the proboscis of Leptoplana is distended by 
injection of body-fluid (Kefersteust, loc. cit. p. 21). In highly magnified transverse 
sections of the penis these wavy bands are seen (Plate XIII. fig. 3) passing inwards 
between the masses of longitudinal muscular fibres, making their way through the dense 
zone of internal circular fibres, and breaking up at the inner verge of this zone into a 
series of fine branches. These branches, as seen in the drawing, which is accurately made 
with the camera lucida, pass through the loose tissue which intervenes between the 
epithelium of the glandular prostatic follicles and the internal circular muscular layer, 
and appear as if they became, in some instances, continuous with the glandular epithelial 
elements themselves. It seemed possible that this should be the case, and that when 
the penis was distended with fluid, a liquid derived from that fluid should be poured out 
by these glands which should serve to dilute the semen. The structure, as shown in the 
drawing, is very remarkable ; but after the examination of an oceanic* Planarian I have 
come to see that the structure in question is a system of muscles retracting the penis. 
Punning along the centre of the wavy bands may usually be seen fine thread-like struc- 
tures, and such are indicated in Plate XIII. fig. 3. It is very probable that these are 
nerves following, as in Leptoplana, the vascular canals. 
In Ehynchodemus the generative organs are somewhat different from those of Bipalium, 
as may be seen from Plate XII. fig. 3 & Plate XI. fig. 7. The penis is larger and longer, 
both actually and still more so in proportion to the size of the body. There is no large 
swelling or bulb at the base of the penis, but a strongly muscular straight canal, of larger 
bore than that which pierces the penis, extends from the base of that organ towards the 
mouth in the middle line, and terminates blindly just opposite the termination of the 
testes. This canal is not provided with any special glandular epithelium, and is pro- 
bably solely ejaculatory in function. The vasa deferentia are wide and tortuous; they 
turn twice upon themselves before they enter the ejaculatory tube, which they join at a 
* This animal came into my hands whilst I was upon H.M.S. ‘ Challenger,’ subsequently to the reading of 
this paper before the Eoyal Society. 
