288 Schonland. — On the Morphology 
a perianth-leaf and an anther. I am inclined to think that his 
view is right, although I cannot offer much additional evidence 
to support it. But I may mention that I have often seen the 
posterior perianth-leaf of lateral flowers forming a compact 
body with the adjoining perianth-leaf of the terminal flower, 
both of them bearing their pollen-sacs in their proper places. 
Now, when we thus see that leaves of different flowers frequently 
coalesce to form a single structure, we are certainly justified 
from a morphological point of view to assume that such a 
coalescence may constantly take place in the leaves of the same 
flower, if there are other reasons to support such an assumption. 
Eichler adduces as an argument in support of his view the fact 
that in other species of Viscum , as also in the nearly allied 
genera Eremolepis , Phoradendron , and others, the two leaves, 
which are only hypothetical in our species, may actually 
become nearly separate; and, further, that it also happens 
exceptionally in these genera that the flowers possess three 
perianth-leaves and two anthers, one of the latter being then 
placed between two of the former, ‘ certainly the best evidence 
against Hofmeister’s view V 
Eichler says that the male lateral flowers are ‘ always ’ 
tetramerous, but I found them frequently to be trimerous or 
even pentamerous. In the trimerous flowers there was appar- 
ently a single whorl of perianth-leaves 2 substituted for the 
normal two dimerous whorls, whereas in the pentamerous 
flowers evidently a splitting of a perianth-leaf with the adnate 
stamen had taken place (compare the diagrams of the lateral 
flowers in Fig. 6). The terminal flowers of shoots with a 
dimerous (and I may add also those with a tetramerous) whorl 
1 See also Schumann in Pringsheim’s Jahrbiicher, 1887, Bd. xviii. p. 133, where 
questions of this kind are treated of in a more general way ; the case of Viscum is 
mentioned on p. 170. My paper was in the hands of the editors before No. VI. 
of the Annals of Botany was published. I have noticed with satisfaction that 
Mr. T. Johnson in his paper in that number, on ‘ Arceuthobium OxycedriJ brings 
forward very strong arguments in support of Eichlers view (cf. Annals of Botany, 
Vol. II. No. VI. pp. 155 and 156). 
2 For shortness’ sake I am only speaking of perianth-leaves here and in the 
following passages. It will be understood that I always mean the structures 
composed of a perianth-leaf and an anther. 
