Analonnj ami Tfistology of a New Earthworm. 77 



Fig. 15.— Cross section through oesophagus, a, Dorsal vessel, b, 

 Oesophagus, c, Blood spaces in walls of oesophagus, d, Chloragogue 

 layer. 



Fig. 16. — Cross section of the body in the region of the rectum. 

 a, Dorsal vessel, h, Kectum. d, Subintestinal blood vessel, e, ven- 

 tral nerve cord. 



PLATE IV. 



Fig. 17. — Section of the body-wall passing through the ducts of 

 the anterior "prostate glands." a, Sections of the embedded vasa 

 deferentia. 6, Ducts of the "prostate glands" passing to the ex- 

 terior, c, Portions of the copulatory setie. d, Ventral nerve cord. 

 e, Longitudinal muscle layer of bodj'-wall. /, Circular muscle layer 

 of body-wall, g, Hypodermis. 



Fig. 18. — a, Locomotor seta, b, Copulatory seta. 



Fig. 19.— Cross section of the ventral nerve cord of anterior part 

 of body, from between ganglia, a, Sheath of large median giant 

 fiber. 6, One of lateral giant fibers, c, Greatly developed muscular 

 sheath of cord. d. Fibrillar nervous tissue invested with connective 

 tissue, e, Axial substance of median giant fiber here drawn to one 

 side. 



Fig. 20. — Dorsal view of cerebral ganglion, a, Xerve which sup- 

 plies region of prostomium. 6, Commissure, c, Muscular bands 

 arising from posterior side of ganglion. 



Fig. 21. — Cross section of ventral nerve cord from posterior part 

 of body through ganglion, a, Median giant fiber. 6, Lateral giant 

 fiber, c, Sheath of cord. cZ, Fibrillar nervous tissue, e, LTnipolar nerve 

 cells. /, Origin of lateral nerve. 



Fig. 22.— Enlarged section of typhlosole and dorsal vessel, show- 

 ing small intestinal vessel entering dorsal vessel at h. a. Left division 

 of dorsal vessel, c. Dorsal vessel of right side, without intestinal 

 branch (due to section not being true), d, Typhlosole. 



PLATE V. 



Fig. 23.— Ovary. 



Fig. 24.— Oviduct. 



Fig. 2.5.— Section of an ovum from the ovary, a, Investing con- 

 nective tissue membrane (probably lost or resorbed when the egg is 

 set free). 6, Nuclei of connective tissue membrane, c, Nucleus of 

 ovum, d. Nucleolus. 



Fig. 26. — Spermatheca. a, Ccecum. b, Duct. 



Fig. 27. — Copulatory fossa greatly enlarged, a, Fossa, b, Vasa 

 deferentia, which unite near the external aperture at c. d, Aperture 

 of " prostate glands ". e, Copulatory setie. 



Fig. 28.- " Prostate gland", a. Duct. 



