ö(3 ART. 8. 1. IKEDA I THKEE NEW AND 



examined by me being sexually ripe females (obtained in No- 

 vember and December), I have found the swollen part of the 

 segmental organ filled with spherical ova of a light yellow color. 



Studies of the segmental organ on sections (figs. 29-31) did 

 not bring to light much structural peculiarities. In fig. 29 is 

 given a sketch of a small portion of the body-wall in cross-section, 

 showing the position of the organs on either side of the ventral 

 nerve-cord (v.n.) and the manner of their opening externally on 

 the ventral surface (ex.o.). The j^art of the out-leading duct 

 directly adjoining the external opening is characterized by being 

 lined with a thick epithelium extremely rich in unicellular 

 glands (fig. 30, (jL). These are of an elongate oval shape, each 

 opening on the external end with a comparatively large and 

 distinct pore. Their contents show a coarse reticular structure, 

 deeply stainable with hematoxylin ; the nucleus is found always 

 near the inner cell end. The true epithelial cells lie so narrowly 

 compressed between the glandular cells that their limits can not 

 be made out {ep.). However, their nuclei can be easily dis- 

 tinguished by their oblong shape, while those of the underlying 

 mesenchyme cells are round and somewhat larger. The main 

 tubular part of the organ has thin wall, the structure of which 

 is shown in fig. 31 in longitudinal section. The internal epithel- 

 ium (epi.), as also the external peritoneal covering (p)'.), is com- 

 })Osed of very flat cells in a layer. Almost in contact with the 

 internal epithelium is a layer of longitudinal muscle fibers {l.m.). 

 Between this and the peritoneum is a connective-tissue layer, in 

 which run a number of muscle fibers in indefinite directions [o.m.). 



With regard to the form and structure of the ciliated funnels 

 (lig. 24, fn.), no point of special interest has come into my 

 notice. 



