688 
.1. DAVlDiSUxV. 
The terminal chambers of the caeca are small, and from 
the distal one is produced a fine thread-like ovarian ligament. 
The oviducts are sliglitly flattened dorso-ventrally, and 
have stout muscular walls, with an inner epithelium of irre- 
gular, columnar cells bounding the duct. 
fl'he vagina is flattened dorso-ventrally, appearing narrow 
in longitudinal sections, but broad when viewed from the 
dorsal or ventral aspect. As seen in fresh preparations, it is 
whitish in colour, semi-transparent, and possesses stout, 
muscular walls. 
The walls consist of a thick, outer layer of circular muscle.®, 
and a few scattered, inner, longitudinal muscles, with aii 
epithelial layer of irregular cells, bordering the cavity 
(fig. 42). 
As the vagina eaves the genital orifice it bends upwards, 
the muscular walls being thrown into folds. 
The genital orifice is wide transversely, and is bounded by 
the genital and anal plates, which bear several stout bristly 
hairs. 
The embryos are squeezed out through the orifice, po.s- 
terior end first, by the muscular action of the vagina Avails. 
As they emerge from the orifice they are smooth and glisten- 
ing, the appendages adhering firmly to the sides of the body. 
The embryos are held by the head in the orifice for a feAv 
minutes after birth, and the anterior appendages are first set 
free from the sides of the body, the other legs being released 
soon afterwards. 
F. The Muscular System. 
The muscular system is well developed. For purposes of 
description the distribution of the various muscles may be 
conveniently treated as follows : 
(1) The longitudinal body muscles. (2) The musculature of 
the head and its appendages. (3) The musculature of the 
thorax and ambulatory appendages. (4) The dorso-ventral 
muscles. 
(1) The Longitudinal Body -muscles (PI. 38, fig. 5 ; 
