198 DESCRIPTION OF PERIPATUS OVIPARUS, 



ovar}^, to which they are attached. Near to its point of oriojin each 

 bears an oval receptaculum seminis with two ducts. It is very 

 important to observe that each oviduct is divided into three parts. 

 All three parts are narrow except where swollen by the contained 

 eggs. The first is very short and extends from the point of 

 attachment to the ovary to about the level of the receptaculum; 

 its wall its greatly folded and provided with little excrescences on 

 the side opposite to the receptaculum. The middle and last 

 portions of the oviduct are of about equal length. The middle 

 portion is very thick-walled and apparently glandular. The last 

 portion has very thin, transparent, membranous walls. At their 

 hinder ends the oviducts unite in a thick-walled triangular sac, 

 whose posterior angle is continued into the ovipositor. 



I have found eggs in both the middle and last portions of the 

 oviduct, but much more abundantly in the last. Their number 

 varies greatly. In one specimen, for example, there were three 

 eggs in each oviduct; in a second there were seven in one and six 

 in the other; in a third there were eight in one and nine in the 

 other. 



The eggs at the time of laying show no appearance of eml^ryos 

 within them, but each consists of a quantity of milky fluid, con- 

 taining numerous yolk granules, enclosed in a very thick, tough, 

 but rather soft envelope of a pale yellow colour and beautifully 

 sculptured on the outside. The sculpturing consists of little 

 crumpled papillae, somewhat resembling worm-casts, arranged at 

 fairly regular intervals over the surface, and with much finer 

 meandering ridges occupying the spaces between them. The eggs 

 are oval in shape and measure about 1*9 by 1 '5 mm. 



A careful re-investigation of my material has led me to tlie 

 following conclusions with regard to the egg-envelope. The 

 envelope really consists of three membranes. (1) A very thin 

 transparent membrane immediately surrounding the yolk and 

 prolmbly to be regarded as a vitelline membrane. (2) A very 

 thick membrane which is apparently formed as a secretion in the 

 thick-walled part of the oviduct. In sections of a female contain- 

 ing eggs in the oviduct this membrane is very clearly shown, and 



