THE BRITISH WOODLICE. 9 
The openings are very difficult to identify, and Lereboullet 
(39, p- 113) was unable to find them. It is obvious that the 
openings must be underneath the plates that form the egg pouch, 
and as a change of skin is required to set these free, it would 
appear that at ordinary seasons the ducts from the ovaries are 
closed. The writers have 
been able to determine J’ MESTES. 
from external examin- oe i es 
ation of specimens which ee 
had moulted and were 
about to lay eggs, that 
the oviducts at such time 
open to the inside of the 
base of each walking leg 
on the fifth segment. In NY. 
similar specimens’ the Ne of 4 : Sentral 
oviducts were also follow- 7 Ree 
ed to the opening from 
within. The brood pouch has 
already been described. 
The male organs con- 
sist of six testes arranged 
in two pairs,each of which 
is provided with a reservoir 
(see fig. 21), The efferent 
ducts from the two reser- 
voirs unite at the base of 
the thorax to form a com- 
mon duct (or‘ penis ”’). Ages 
en tee one i Cs ‘, 
abdominn wmpcrages 
eggs, in the common 
species of woodlice, at FIG, 21.—THE MALE REPRODUCTORY ORGANS, 
Z (Ontscus asellus.) 
least, are laid at the 
beginning of summer, and are retained in the brood pouch, 
where they undergo their development. The process has been 
recently traced with great care by Professor Louis Roule (58) 
in Porcellio scaber and the description which follows is based 
upon his researches. 
As, practically speaking, the larval stages are passed within 
the egg, and there is no free embryo differing in form from the 
