Johnson . — On Arceuthobium Oxycedri. 155 
has the fibrous markings typical of the sub-epidermal 
layer of cells of an ordinary anther (Fig. 13). The ta- 
petum is represented by yellowish brown spheroidal bodies 
averaging ^oVo inch in diameter. The structure of the pollen- 
grain at this stage (Fig. 14) comes out very clearly, and is 
normal. Still further reduction is noticeable of the staminal 
leaf ; the stamen has no vascular bundle. The single vascular 
bundle of the perianth segment on which the stamen occurs 
makes a slight bend towards the stamen beneath its insertion, 
and one or two of the vessels may point a little towards it, but 
there is no indication of an independent vascular supply in the 
stamen. On making longitudinal sections of a very young 
flower, the expansion of which would have happened in the 
following year, the development of the flower as a whole and 
of its several parts can be ascertained. The position of the 
stamen is seen to be very different from that in the expanded 
flower. It arises as a multicellular lateral outgrowth of the 
floral axis, independently of the perianth-segment, and acquires 
its final position by the intercalation of the lower half of the 
perianth-segment as a belt of tissue common to the stamen 
and perianth-segment (Fig. 1 5). 
Whilst this observation may do nothing to further the 
elucidation of the precise nature of the perianth-segment, 
whether it is a sepal or a petal, it does strongly support 
Eichler’s opinion 1 of the nature of the andrcecium in the 
Visceae : — ‘The anther of Viscum is so completely fused with 
the perianth-leaf, even in its early stages, that Hofmeister 
regards the two as forming only one phyllome. Van Tieghem, 
who agrees with this determination, quotes in support of it 
the presence of one vascular bundle in the organ. I must 
however adhere to the old statement, that we have to do here 
with a very intimate fusion of two different leaves ; for not only 
in different species of Viscum itself, but also in closely allied 
genera, Eremolepis , Phoradendron , &c., the two leaves can be 
so fully isolated that they often show only a faint fusion 
1 Eichler, Bluthendiagrarnme, p. 556. 
M 2 
