TWO NEW SPECIES OF CESTODES. 277 
tube, which gives off ovai diverticula laterally. These cavities 
have well-marked walls, which, however, do not seem to be 
independent of the surrounding parenchyma; they have no 
special lining of their own. Later the cavities are multiplied, 
and the eggs from the very first are confined to these cavities 
and never lie in the parenchyma between them. The uterus, 
moreover, exists throughout a good many proglottids. On the 
other hand, in Linstowia ameive the uterine cavities are less 
strongly marked off and altogether less definite ; they do not 
form a coherent group and exist for a much shorter period. 
Moreover, from the very first the ripe ova do not all of them lie 
within these cavities ; they are continually to be found imbedded 
in the parenchyma between the uterine cavities. The uterus 
seems to be degenerating in this species as compared with that 
of O. marmose. 
Text-figure 7. 
A portion of the same mere highly maguiuce. 
The membranes surrounding the embryo (e.) are not yet formed. 
The disappearance of the uterus in Oochoristica marmose. is 
followed by a stage (illustrated in text-fig. 6) in which the eggs, 
which have by this time developed into embryos, are uniformly 
scattered through the medulla (occasionally invading the cortical 
layer, as already mentioned) for a considerable number of pro- 
glottids, which I am unable to state exactly; the scattered 
embryos possess no definite shell. They lie (text-fig. 7) in 
cavities of uniform size separated by meshwork from each other. 
These cavities resemble in every way the cavities of the paren- 
chyma in various tapeworms, where there is no question of 
uterine cavities. It must be admitted, however, that such a 
space as there is round an individual embryo is to be looked 
