584 DR. M. T. MASTERS: GENERAL VIEW 
by branching above and sending one branch to the bract, whilst 
the other enters the scale. The central woody core of the ripe 
cone is spindle-shaped. Cotyledons 8-14. 
In some parts of the Swiss Alps, as near Zermatt, where the 
tree reaches to within a short distance of the snow-line, this 
species appears to be gradually dying out, and no steps seem to 
be taken to preserve so valuable a tree. 
The species has a very wide distribution ; but it is possible 
that some forms usually included within its limitations are really 
distinct. Thus, Mayr says that the var. pumila is a distinct 
species having marginal, not central resin-canals ; whilst the 
Pinus mandshurica of Ruprecht, also referred to this species, is 
considered by Maximowicz to be referable to P. koraiensis (see 
Melanges Biolog. xi.). 
14, Pints MonopHYLLA, Torrey; Sargent, Silva, xi. (1897) 
p- 51, t. 551. 
This, which is equivalent to the P. Fremontiana of Endlicher. 
is a native of Nevada, Utah, San Diego, California, Arizona, and 
the northern slopes of the San Bernardino Mts. It is remarkable 
for its leaves standing singly, and not in tufts. Various expla- 
nations have been offered of this peculiarity. In the ‘ Annals of 
Botany,’ ii. (1888), I have given reasons for supposing that the 
single leaf is truly a leaf in structure and position, and that its 
isolation is due to the arrested development of its companion 
leaf. Occasionally this second leaf passes on to its full develop- 
ment, when a two-leaved fascicle results. 
The cells of the mesophyll have infolded undulating processes. 
The resin-canals are marginal, surrounded by strengthening cells, 
and the meristele is circular in section, with an unbranched fibro- 
vascular bundle. The endoderm-layer consists of about 50 cells 
(Pl. 21. fig. 4). The cylindrical form of the leaf and of the 
stele are evidently due to the development of the leaf when not 
restricted by contact with its fellow leaf. The bracts sur- 
rounding the male flowers are six in number (Sargent). 
The apophysis of the cone-scales is convex, shining chestnut- 
brown, with an elliptical grey umbo. Cotyledons 8-10. 
In cultivation adventitious shoots or “novelli,” bearing flattish 
primordial leaves sometimes called squame@e fulcrantes, are occa- 
sionally produced from the lower branches. 
An interesting account, with illustrations, was given of this 
a 
