290 
Schonland. — On the Morphology 
as in Fig. 8 II, this whorl is placed transversely, assuming the 
position of the scale-leaves which are wanting. I have tested 
this fact in many cases, and always with the same result. I am 
thus led to believe that the difference between the terminal 
male and female flowers, with regard to the position of their 
parts, is simply caused by the complete suppression in the 
former of the uppermost (fourth) pair of leaves. 
An increase in the number of parts composing the male 
terminal flowers is not rare. Eichler only knew of pentamerous 
and hexamerous flowers besides the normal ones; but I have 
also observed one heptamerous and one decamerous flower 1 . 
Eichler explained the abnormal cases known to him by 
assuming that in the hexamerous flowers the inner dimerous 
whorl of normal flowers was replaced by a whorl of four 
members, and in the pentamerous flowers by a whorl of three ; 
but his own figure, which I have copied (Fig. 9), suggests at 
once the idea that the increase is simply due to the splitting 
of the two normal members composing the inner whorl 2 . I 
have already adopted such an explanation in the case of the 
pentamerous lateral flowers, where I usually found it to agree 
extremely well with the position of the parts of the flowers. 
In the terminal flowers a regular arrangement of the parts 
cannot always be recognised when their number has been 
increased, but it is easy to find all intermediate stages between 
perianth-leaves only slightly divided at the top, and others 
which are divided down to the base. My explanation covers 
also the cases in which seven and ten perianth-leaves were 
found, whereas those adopting Eichler’s view would find 
difficulty in explaining them. The view that the increase 
is due to splitting may perhaps be strengthened still more 
when I restate the fact, which I hope has been distinctly proved, 
that splitting of foliage-leaves also occurs in the mistletoe. 
1 The hexamerous flowers of shoots with three foliage-leaves were also ap- 
parently unknown to him, but these must be left out of account here, as in a certain 
sense they have to be considered as normal. 
2 I may here call attention to the similarity between our case and the interpre- 
tation of the androecium of Cruciferae, regarding which Eichler holds exactly the 
view I take of it in Viscum. 
