200 PROF. HUXLEY ON THE AGAMIC REPRODUCTION 
nti itheli continuous with the contents of the cham- 
e mere = pret se by a homogeneous pale periplastie 
peng å ed a doves clear spheroidal cavities (e) whose walls are 
eene e» a of the periplast. The cavities have on an average a dia- 
es ang an ies In the centre of each is a rounded opake body (/) like 
gas om aA of the wall of the dilatation, and, indeed, obviously of the same — 
i fluid I have examined this tíssue, it began after a time to alter. In the 
very weak syrup which I ordinarily employed, the change consisted partly in Wm 
increased definition of the walls of the clear cavity, but more particularly in the € 
up of the periplast into spheroidal masses, each of which contained a single ees e Y 
its endoplast*. The resemblance of such a body to an ovum with its germin vesi på 
and spot is complete; nor would it be possible for any one ignorant of the origin 
the body to say that it was other than an ovum. Water instantly alters the appa 
of the tissue, completely destroying its distinctive character. Dilute glycerine shrivels 
up the vesicles and alters the appearance of their central endoplast, probably by endos- 
mose. Acetic acid renders the periplast dark, and gives an exceedingly marked definition 
to the parietes of the vesicle. To see the appearances I have described as normal, the part 
must be examined perfectly fresh, and in a solution of sugar neither too dilute nor too 
concentrated. 
In certain specimens the contents of the lower part of the terminal chamber are dif- 
ferent from those of the upper. As much as a third of the whole chamber may be bests: 
pied by a mass of periplast containing only a single clear vesicle. Such 6 CORE is 
figured in fig. 1, Pl. XXXVI. Fig. 2 exhibits a further advance in the same direction; thie 
mass, which, from its close resemblance to a true ovum, I have called a pseudovum, having 
enlarged so much as nearly to equal the contents of the terminal chamber, from which it is 
distinguished by a slight constriction. In figs. 3 and 4, the constriction has become — 
marked, until at length à penultimate chamber is formed, connected only by a narrow neck 
with the terminal one, fig. 4. It is on an average about s5sth of an inch in diameter. The 
epithelial layer (c) of its wall is ordinarily well developed, and when water is added swells 
up, So as to separate the periplastic substance of the pseudovum from the wall. The pert 
plast itself exhibited no structure, and appeared unchanged except in size. The e 
vesicle was sometimes unchanged, sometimes enlarged, but otherwise unaltered. Of its 
endoplast I was sometimes unable to diseover any trace; on other occasions I found a 
few granules in its place (fig. 3); and, once, two particles, each rather more than half - 
diameter, appeared to lie side by side in the interior of the vesicle. : 
The marked contrast between the perfect distinctness of the endoplast in the vesicles 
contained in the ultimate pseudovarian chamber, and its apparent absence in the ye 
similar vesicle of the mass contained in the penultimate chamber, or in the lower part 0 
the last one, was the more striking, as the two could be readily compared under the same UE 
circumstances and in the same field of view. 
å li dig (1: e. p. 63) appears to regard this as the first state of the ovigerms, and he has overlooked ME 
epithelium, å 
