THE GIANT EARTH-WORM OF GIPPSLAND. 59 
which are continued down into the duct, and extend backwards into the body of the 
nephridium. The funnel is enclosed in a sheath of connective tissue, amongst which 
_lie many circularly disposed muscle fibres. 
Fig. 27.—Diagram to show the relationship of the nephridia. Three smaller 
nephridia are shown, and one larger one. Two of the smaller belong to the same 
segment as the larger one (neph. 1.) These two smaller ones open into a longitudinal 
intra-cellular duct (d.) running beneath the ccelomic epithelium ; into this opens the 
larger nephridium, from which a finer duct runs forward through the septum to the 
nephridial funnel. A small duct passes beneath the septum to the next segment, 
opening into the longitudinal duct, which is connected with the small nephridium. 
The ducts are indicated in the figure by the parts more darkly shaded. From the 
longitudinal duct arise at intervals (and having no constant relationship to the 
nephridia) a series of ducts leading down through the body wall. Within the muscle 
layers, the ducts change from being intra to inter-cellular in nature. The inter-cellular 
ducts usually branch, and each branch has its own external opening, at which the 
cells of the epidermis become modified. 
Fig. 28.—Section through the external opening of a small nephridium in the 
clitellar region. The duct, with its very thin walls, is vesicular in nature, and the 
thin film-like pavement epithelium is distinguishable by its slightly granular 
appearance, and its large oval nuclei, irregularly arranged. Where an optical section 
is obtained at the edges, the nuclei are seen to cause bulgings in the wall, which is 
darkly coloured in the drawing. ‘The epidermic cells are arranged at the external 
opening so as to form a spherical structure, through the centre of which the duct 
runs, its walls being continuous with the cells forming the axis of the sphere. These 
are more darkly stained (ef.') than the other cells (é.”), and no nuclei could be 
detected in them. The cuticle is not prolonged into the duct, and just where the 
latter enters the epidermis are a few muscle cells, acting, doubtless, as a sphincter (m.) 
Zeiss, obj. apo. 2mm. Ocular compens. 18. Magnifying power, 2,250. 
Fig. 29.—Section through part of the wall of the prostate gland. The cells 
lying internally (sf.*) are more darkly stained than the outer ones, into which they 
sometimes project, and contain no nuclei. The outer cells (sf.") have swollen ends, 
and ducts running towards the inner surface of the gland, and contain nuclei. 
Pigment masses of a yellow-brown colour occur on the outer edge of the organ, 
beneath the enclosing connective tissue. Zerrss F., ocular 4. 
Fig. 30.—Diagrammatic longitudinal vertical section through the segments 
containing the vasa deferentia. The openings into the body cavity of the two are 
shown, the funnels being composed of cubical ciliated cells, and being hence very 
unlike the nephridial funnels. The vasa deferentia run back quite independently of 
each other into the prostate gland, certain of the segments being omitted in the 
figure. The ducts lie in the connective tissue just above the longitudinal muscle 
12 
