Behind this the cords present a series of enlargements, one pair for each pair of feet, from which a pair of large nerves pass off on each side to the feet (_p.n_). _at.n._ Antennary nerves. _co._ Commissures between ventral cords. _d._ Ventral appendages of brain. E. Eye. _e.n._ Nerves passing outwards from ventral cord. _F.g._ Ganglionic enlargements from which nerves to feet pass off. _j.n._ Nerves to jaws. _or.g._ Ganglionic enlargement from which nerves to oral papillæ pass off. _or.n._ Nerves to oral papillæ. _p.c._ Posterior lobe of brain. _p.n._ Nerves to feet. _s.y._ Sympathetic nerves. Fig. 23. "Longitudinal horizontal section through the head of _Peripatus capensis_, shewing the structure of the brain, the antennary and optic nerves, &c. (Zeiss a a, Hartnack's camera.)" _at._ Antenna. _at.n._ Antennary nerve. _cor._ Cornea. _e._ Central mass of white matter. _l._ Lens. _op.n._ Optic nerve. _ph._ Pharynx. _p.p._ Primary papilla covered with secondary papillæ and terminating in a long spine. _sy._ Pharyngeal sympathetic nerves. Fig. 24. "Eye of _Peripatus capensis_, as shewn in a longitudinal horizontal section through the head. The figure is so far diagrammatic that the lens is represented as filling up the whole space between the rods and the cornea. In the actual section there is a considerable space between the parts, but this space is probably artificial, being in part caused by the shrinkage of the lens and in part by the action of the razor. (Zeiss C, Hartnack's camera.)" (It appears that the ganglionic region of the eye is covered by a thin capsule, which is omitted in the figure.) _cor._ Cornea. _l._ Lens. _op._ Optic ganglion. _op.n._ Optic nerve. _pi.r._ Pigment. _Re._ rods. _s.p._ Secondary papillæ. Fig. 25. Longitudinal horizontal section through the dorsal skin, shewing the peculiar arrangement of the circular muscular fibres. (Zeiss A, Hartnack's camera.) PLATE 52. Fig. 26. Portion of ventral cord of _Peripatus capensis_ enlarged, shewing two ganglionic enlargements and the origin of the nerves and commissures. (From a drawing by Miss Balfour.) _co._ Commissures. E._n._ Nerves passing out from ventral cords. F._n._ Nerves to feet. _g.co._ Commissures between the ventral cords containing ganglion cells. _v.g._ Ganglionic enlargements. Fig. 27. Segmental organ from the 5th pair of legs of _Peripatus capensis_. This nephridium resembles those of the 4th legs, and differs from all the others in its large size and in the absence of any dilatation giving rise to a collecting vesicle on its external portion (enlarged). The terminal portion has the same histological characters as in the case of the hinder segmental organs. (From a drawing by Miss Balfour.)