The adult organisation of Paragordius varius. 461 
uterus join with the intestine to compose a cloaca. In the males of 
the Nematoda there is generally an unpaired, tubular, non-segmented 
testis which opens into a cloaca; but in some forms, according to 
BUTSCHLI (1874), there is a pair of testes. In the Annelida, on 
the other hand, the ovaries and testes are not tubular organs, they 
also do not connect with the intestine, but are proliferations, often 
but not always metameric in arrangement, of the peritoneum; the 
germ cells from these centres of growth fall into the coelom, and from 
there arrive at the exterior either by way of nephridia (or modified 
nephridia), or else by rupture of the body wall. Now in the Gor- 
diacea there are paired, tubular genital organs in both sexes, opening 
into a cloaca. In the male the structure is simpler: a pair of long, 
completely closed, non-segmented tubes, the testes (VEJDoVsKY terms 
only their anterior ends testes), lined by a germinal epithelium. Here 
is then a great similarity to the case of those Nematoda with a pair 
of testes. In the female of the Gordiacea occur, in addition to the 
pair of long uteri (which seem in position comparable to the testes 
of the male), also numerous paired sacks lying in the lateral body 
cavities and each connected by an opening with the cavity of the 
uterus of the corresponding side of the body. VEspovskY¥ first showed 
these sacks (his “Eiersäcke”) to be segmentally arranged, and that 
each developes as an evagination of the wall of a uterus. On account 
of such segmentally arranged “Eiersäcke”, and their first beginnings, 
the “Eierstöcke”, VEJDOVSKY concluded the ovaries of the Gordia- 
cea to be bilaterally and segmentally arranged, and so to agree with 
the Annelidan type. But in the descriptive part of this paper I have 
given reasons for concluding that the uteri together with these Eier- 
säcke must be considered as composing a single long pair of ovaries, 
that is, a pair of ovaries each with numerous lateral diverticula. For 
both are lined by the same kind of epithelium; the cavities of the 
lateral diverticula (at least in Paragordius) communicate only with 
the cavities of the uteri, and not into the lateral body cavities; and 
the points of proliferation of the ova are where the diverticula first 
arise as outgrowths from the walls of the uteri, so that the germinal 
epithelium is as much part of the so-called uteri as of the so-called 
ovaries. The term “ovary” in the strict sense of course signifies 
the place where the growth of ova takes place; but in general usage 
it means also the place characterised by the presence of a germinal 
epithelium, whether all portions of this epithelium proliferate ova or 
not. VEJDOVSKY himself has shown (1894) that at an early stage the 
