of the Mistletoe ( Viscum album , LI). 285 
bear an axillary bud, and thus true whorls of three or four 
branches may also be produced. I have actually observed 
such true whorls of three and four branches. The structure 
of the inflorescence, moreover, corresponds usually to the 
number of foliage-leaves, as we shall see later. In one case 
only, where three foliage-leaves occurred, they seemed to have 
arisen from the normal two leaves. One of the three leaves 
was rather broad, and showed beginning of splitting at the 
apex, while two others were about the normal size ; but neither 
one nor the other of these had, like the third, a bud in its axil, 
there was, however, a bud between them, which served, as it 
were, as a common axillary bud for the two together (Fig. 
3). It is probable, therefore, that they owed their origin to 
the splitting of one of the normal leaves. The odd leaf of the 
true trimerous whorls of foliage-leaves is always turned towards 
the axis (Figs. 4, 5 I), whereas the leaves of the tetramerous 
whorls are placed diagonally (Fig. 5 h, 6). 
The inflorescences are usually found between the two foliage- 
leaves, and normally consist of two lateral flowers at right 
angles to these leaves, and a terminal flower. Each of the 
former stands in the axil of a small scale-leaf, the two together 
thus forming a third whorl of leaves ( s , s, Figs. 1, 2). No 
more leaves are borne directly by the primary axis of each 
shoot in the male plants, but in the female plants the terminal 
flower is usually preceded by a fourth pair of leaves, which is 
like the one preceding it, and continues the regular decussate 
arrangement of leaves 1 (s 1 , s\ Fig. 1). Where three or four 
foliage-leaves are borne by a shoot, the number of the upper 
scale-leaves is increased at the same rate ; this is often also the 
case with the lateral flowers, but frequently their full number 
is not developed (Figs. 5 I and 5 II). Very often scale-leaves are 
only developed where foliage-leaves ought to be, either in the 
place of one or of both of a pair. This occurs chiefly in shoots 
which have been dormant one or more years. Very commonly 
these additional scale-leaves also bear flowers in their axils, 
1 From a remark made by Wydler, Flora, i860, p. 443, I conclude they may 
also bear flowers in their axils. 
