4.60 WwW. A. HASWELL. 
the cavity of the uterus, and into that of the bursa copulatrix, 
open the ducts of numerous unicellular glands—the shell 
glands,—which lie all round this part of the reproductive 
apparatus, and reach nearly as far as the lateral margin of 
the body. When an egg is not present in the uterus, the 
latter contains a quantity of fibrillar matter, which is perhaps 
coagulated secretion from the shell glands. In one living 
specimen the bursa copulatrix was observed to contain a 
number of rounded yellow globules, somewhat smaller than 
the vitelline spherules. These perhaps consist of the secre- 
tion of the shell glands, of which this sac may perhaps act as 
@ reservoir. 
In many specimens an egg was found in the uterus. Its 
shell was always so thick and opaque as to prevent any satis- 
factory view of its contents being obtained, except in one 
instance in which the formation of the egg-shell was incom- 
plete. Hmnclosed within the transparent egg-shell in this 
specimen was the unsegmented oosperm surrounded by a mass 
of yolk-corpuscles. ‘The oosperm was ‘06 mm. in diameter, 
the corpuscles, on an average, about ‘04 mm. 
The vitelline glands form a continuous network extending 
throughout all the post-pharyngeal region. In the cytoplasm 
of the cells two kinds of material are produced. One of these 
appears first as extremely fine spherical granules or droplets, 
which become stained with eosin. These become aggregated 
into larger masses. ‘The other substance is not colourable ; 
it forms larger irregular masses. ‘l'hese two sets of elements 
escape from the cell into the irregular lumen of the gland; 
there is no evidence that the cell itself breaks up to form a 
part of the vitelline substance, and no evidence of the active 
cell-multiplication which such a process would entail. 
Moreover, in the completed egg the very characteristic and 
readily-recognisable nuclei of the vitelline cells are not to be 
recognised. 
1 Von Graff (14) describes a breaking down of the vitelline cells in Turbell- 
aria in general, and Hallez (18) speaks of a continuous multiplication by 
division. ; 
