Johnson. — On Arceuthobium Oxycedri . 139 
of September or beginning of October) and in such a direction 
as to pass through the median plane of the two perianth-seg- 
ments, the unilocular inferior ovary will be seen to be almost 
entirely filled by a conical cellular papilla continuous with the 
cells forming the floor of the ovary and projecting freely into 
the ovarian cavity. On the surface of the cone lie the dis- 
tinctly columnar cells of the continuous epidermis and beneath 
it is a mass of cellular tissue, near the apex of which two 
large ovoid cells occur, one towards each side of the axis 
of the papilla, and having their outer sides parallel and in 
contact with the epidermis (Fig. 1). These are two embryo- 
sacs, and they are obliquely inclined towards one another, and 
only separated at their upper, usually broader ends by one or 
two median cells of the papilla. 
Each embryo-sac has a thick highly refractive pitted cellulose 
wall enclosing very abundant and granular protoplasm. In 
a successful preparation the arrangement of the cells in the 
interior of this embryo-sac may be ascertained, as shown in 
Figure 2. 
Though I was not able to see all the stages from the 
uninucleate condition to that in which the embryo-sac is ready 
for fertilisation, I saw enough to convince me that the develop- 
ment is as in a normal Angiosperm. In one embryo-sac there 
was at the antipodal end a resting nucleus and one in 
the segmentation stage, in another there were two nuclei 
meeting in the middle of the embryo-sac, and other inter- 
mediate stages were observed. The antipodal cells of the 
embryo-sac were in all cases quite distinct ; but it was different 
with the egg-apparatus. Both synergidal cells and oosphere 
were often so obscure that their presence could not be 
ascertained with certainty. This negative result may have 
been due partly to the exceeding granularity and tendency 
to opacity of the general protoplasm, and partly to the 
faintness of the nuclei themselves, a phenomenon which has 
been observed in other parasites 1 . In several cases however, 
1 Hofmeister records this of Viscum album. This is the more strange since the 
nuclei in the other parts of parasites are usually so distinct. 
