STRUCTURE AND DEVELOPMENT OF LOXOSOMA. 283 
in the ovum do not seem to be provided with a nucleus, 
although there can be little doubt that they are really of 
cellular nature, whilst the “ gland-cells ” of L. Tethyae are 
usually true nucleated cells. In spite of this difference, I can 
see no course open but to suppose that these “ gland-cells ” 
lose their nuclei, and are absorbed by the ova in the manner 
indicated by the figure. If this is really the case, it is difficult 
to believe that the bodies in question really have the nature 
of gland-cells, and it is possible that they may belong to the 
mesoderm, and have no connection with the exterior. 1 
Whatever the origin of the vitelline masses observed in the 
nearly ripe ovum, it is a fact of some interest that the yolk in 
L. Tethyae appears to be prepared in part by cells which have 
no connection with the ovary, and that the vitellarium is 
probably not a modification of a primordial germinal mass 
containing potentially both yolk-gland and ovary. In L. 
Leptoclini, the only other species which I have found sexually 
mature at Naples in considerable quantities, I have not observed 
any processes for the nutrition of the ovum comparable to either 
of the methods described inL. Tethyae; and it is a noteworthy 
fact that the “ gland-cells ” of this species differ in their 
histological character from any cells occurring in the other 
species which I have examined. 
It is difficult to reconcile some of the statements of Schmidt 
with the appearance of my own preparations of the generative 
organs of the Entoprocta. I have been unfortunately unable 
to study in detail the structure of the generative organs of 
L. pes, the form specially investigated by Schmidt (11 and 20), 
and I have reason to believe that these generative organs do 
1 In position, the “gland cells” of L. Tethyae correspond with the 
“apical cells” ( ac ., fig. 2) of L. Leptoclini, except for their greater 
lateral extension (nearly as far as the middle of the calyx on each side) in the 
former species. It appears to me not improbable that these two sets of 
structures are homologous, although I have in L. Leptoclini no evidence 
as to their nature. Perhaps in this species the cells, originally playing the 
same part as those of L. Tethyae, are at present mere functionless rudi- 
ments. 
