64 DRS. CARPENTER AND CLAPAR&DE ON TOMOPTERIS ONISCIFORMIS. 
same 
A considerable number of males came under our notice before we met with any 
specimens whose female sexuality was indicated by the presence of ova : of these, how- 
ever, we subsequently encountered several ; and our observations on them are in accord- 
ance with those previously made by Huxley, Busch, and Leuckart and Pagenstecher. 
In a mature female (fig. 1) the ova are to be seen lying, in great numbers and in 
various stages of development, in every part of the perivisceral cavity of the body and 
of its caudal prolongation, and also in the extensions of that cavity into the lateral 
appendages, including even the basal portion of the second antennEe. From a compa- 
rison of the conditions under which they may be seen in one and the same individual, 
it becomes obvious that they originate in the terminal wall of the cavity of the pin- 
nulated appendages,— a fact that seems to have been first recorded by Drs. Leuckart and 
Pagenstecher, though we learn from Mr. Huxley that he had arrived at the 
elusion ten years ago. This terminal wall, which gives support on its outer side to the 
bases of the pinnulae, presents on its inner surface a number of transparent tubercular 
elevations (fig. 7. e), which progressively become hemispherical, then pear-shaped, and 
finally give exit to peculiar nucleated cells which float in the fluid of the perivisceral 
cavity. These cells multiply by self- division after the ordinary mode (fig. 13) ; and it is 
only after their number has thus been considerably augmented, that they begin to increase 
in size and to assume the characteristic appearance of ova. It is not only in the lateral 
appendages of the body, however, that ova thus originate ; for it is clear to us that they 
are developed also in the caudal prolongation ; and it would seem probable (though we 
could not satisfy ourselves of the fact) that they there originate in the corresponding 
situation—that is, on the terminal walls of those extensions of the perivisceral cavity into 
the rudimentary appendages, which, as just shown, are the seat of the testes in the male. 
It is a fact not to be passed without mention, that rudimentary ovaria are to be seen 
in mature males,— the terminal walls of the lateral appendages of the body presenting 
those tubercular elevations whose presence constitutes the first stage in the development of 
ova in the female. Whether at some other period these may develope ova (as is the case 
with certain other worms, which are really hermaphrodite, but which mature their male 
and their female products at different periods), or whether they are merely persistent 
rudiments not destined to undergo any further development (like the mammary glands of 
the male mammal), is a question to be determined by future observation. 
AY e have not been able to detect the mode in which the ova make their exit from the 
body,— the transverse fissures in the outer wall of the perivisceral cavity, which are de- 
scribed by Leuckart and Pagenstecher as presenting themselves in the third and fourth 
segments, not having been noticed by us, probably because they had not yet been formed. 
J> or nave we been able to satisfy ourselves whether the ova are fecundated before their 
escape, by the entrance of spermatozoa through the ciliated canals into the perivisceral 
cavi y, or whether they receive the fertilizing influence after their emergence. 
Although we have had no opportunity of following out the development of this inter- 
l^JZ t r* ^ lt haS bGen the S° od ^tune of one of us to capture, off the 
the t™ ™ h t ^ r^ d ° UH fr ° m the «*fonni* of its general organization to 
the type we have been describing, to be a very early form of the same Tomopteris. This 
