26 MEYEN ON VEGETABLE IMPREGNATION 
and even triplication of the root end which the seed of Viscum 
exhibits on germination, appears, however, to me to have as little 
to do with the plurality of the embryos as the greater number 
of cotyledons in the seed of the true Conifere. 
The above explanation of Treviranus of the duplication and 
triplication of the root end of the embryo of Viscum album, in- 
duced me to make a more accurate examination of the impreg- 
nation and formation of the embryo in this highly interesting 
plant. The female flower of Viscum has, perhaps, with reference 
to the ovule, the simplest structure which can be imagined in a 
phanerogamous plant. There is in Visewm no distinct pistil, and 
consequently no true ovarium ; but the ovule is a simple naked 
nucleus, whose summit projects free, and at the same time 
serves as stigma, as it receives the pollen direct. This naked 
nucleus (figs. 1,2 and 3. Pl. I.) is inclosed all round with a 
ealyx-like organ, upon which are seated four other leaf-like 
organs, which have sometimes been asserted to be sepals, some- 
times petals; I shall here adopt the latter denomination. The 
drawing (fig. 3. Pl. I.) made with an amplification of about 40 
with the simple microscope, will give a sufficient view of the 
structure of the female flower of our plant. / is the naked nu- 
cleus, the base of which is designated with f*, and whose ex- 
panding summit g, clothed with small papilla, supplies the place 
of the stigma of the pistil, which is here absent. On the calycoid 
organ, which surrounds the nucleus, two separate layers are distin- 
guished, both by their outer limitation and by their inner struc- 
ture,anouter andan inner one ; they are mosteasily distinguished 
from eachother by the course of the bundles of spiral tubes,which, 
in direct continuation of the ligneous bundles of the stalk, proceed 
through the short flower-stalk, and pass to the petals. In fig. 3. 
Pl. I. the structure of the female flower is completely and di- 
stinctly represented in a longitudinal section. The letters sig- 
nify the same as in fig. 1: fis the naked nucleus, g its summit, 
and f* its base; next to this nucleus is situated the interior 
layer of the calycoid organ ¢¢, which is separated by the spiral- 
tube-bundles e e, from the outer layer 64. The spiral-tube- 
bundles e e proceed immediately to the petals dd; there are 
four to five such bundles in the calyx; some present ramifica- 
tions, and from these originate various anastomoses, which may 
be seen most easily on the ripe fruits. 
From the lateness of the spring this year, it was not till to- 
