258 ZOOLOGY. 
Besides this set of five cephalic ganglia, there are three pairg 
of ganglia belonging to the visceral or sympathetic nerve, 
which arise from the visceral ganglion situated among the 
viscera ; a single one (the ventricular or splanchnic ganglion) 
is situated over the stomach near the origin of the aorta, 
which sends a nerve to the cecum, and another accompanies 
the aorta; the mate to this ganglion is situated near the 
vena cava. <A pair of ganglia is situated on the mantle walls 
(ganglia stellata), and there are two branchial 
ganglia. The kidneys (%) are irregular 
branching spongy bodies, in intimate con- 
nection with the auricles or branchial hearts. 
The sexes are distinct. The ovary (0) is 
large, especially when the eggs are ripe, and 
is situated in the end of the body-cavity. 
The single oviduct is as in some worms, 
separate from the ovary, and in this respect 
the Cephalopods approach or anticipate the 
Vertebrates, in which the oviduct is also 
separate from the ovary. The oviduct 
(ov) is a thick straight tube, with a flaring, 
deeply-lobed mouth. The eggs,when ex- 
truded, are enveloped in a large gelatinous 
capsule (Fig. 211), which is secreted by the 
large flattened nidamental gland (c) on the 
floor of the body-cavity, tied down at each 
end by cord-like membranes. Usually there 
wef iohie eoak, are two nidamental glands. 
~~After Verrill. The earliest phase of development of the egg 
of most Cephalopods (Sepia, Loligo) is like that of birds and 
reptiles, the yolk undergoing partial segmentation, the blasto- 
derm being restricted to a small disk, asin Vertebrates. Even- 
tually the blastoderm encloses the whole yolk, the mantle 
begins to form, the eyes are at first in-pushings of the outer 
germ-layer, and the mouth appears. The digestive tract 
originates from a primitive invagination of the outer germ- 
layer (ectoderm), as in Amphiozus, Ascidians, worms, and 
some Colenterates. About the tenth day, as observed by 
Ussow, at Naples, the gills, siphon or funnel, and arms arise, 
