230 u long by 27 p wide. 
WOOD 
OF 
HIMALAYAN JUNIPERS. 
5 
Sometimes the cells oceur in pairs, but the width 
of the two is rarely more than that of a single normal cell. 
In normal 
cells the end-walls usually show local thickenings, either solitary in the 
middle or as a series across the wall. 
The lateral walls possess pits which are mostly simple on the radial and 
bordered on the tangential walls, with occasional bordered ones on the radial 
walls. 
Where the pits are bordered they are round with an oval orifice, and 
similar to those occurring on the tangential walls of the summer tracheids. 
In none of the four species do the resin cells form acontinuous longitudinal 
series, but are interrupted at intervals by ordinary wood-tracheids. 
In J. Wallichiana in one instance an aggregation of short resin cell- 
structures appeared to form a resin cyst (fig. 6), but probably this repre- 
sented a pathological condition. 
The position of the resin cells in the growth-ring gives a ready way of 
identifying the species in transverse section. 
Summarising the distinguishing characters of the four species they are as 
follows :— 
Growth-rings. ...... 
; Number of growth- 
rings per inch of 
radius, 
Medullary Rays. 
| Distance away from 
| each other tan- 
| gentially. 
| Height, tangential. 
| Pits on lateral walls 
| per wood-tracheid. 
‚ Shape of pits 
Number of pits on 
wood-tracheids. 
Resin Cells, 
| | 
losen … 
| | 
| Length EM 
| Width ZEN 
| 
J, recurva. 
J. Wallichiana, 
J. macropoda, 
Narrow. 
| " 
1-10 
tracheids. 
1-8 cells. 
| 1-4 
Round, small, ori- 
fice long and slit- 
like, extending 
beyond border. 
Not numerous, 
Somewhat scattered 
in middle of ring 
and extending to 
third row of tra- 
cheids from outer 
limit of growth- 
ring. 
Wide. 
1-12 
tracheids. 
1-18 cells. 
1-4 
Round, orifice oval, 
occasionally ex- 
tending beyond 
border. 
Fairly numerous, 
Zonate ; 
occurring between 
middle of ring and 
fourth row of tra- 
cheids from the 
outer limit. 
230 y. 
27 y. 
Narrow. 
41-42 
1-12 
tracheids. 
1-18 eells. 
1-4 
Round, orifice oval, 
hardly ever ex- 
tending beyond 
border. 
Very numerous, of- 
ten touching each 
other, round to 
elliptical in shape. 
Zonate ; 
always occurring up 
tolimit of growth- 
ring, never more 
than 4-6 tracheids 
from limitof year’s 
growth. Some- 
times in early 
spring wood. 
65-88 pn. 
3-5 p rad. 
16 u tang. 
J. communis, 
Wide. 
1-8 
occasionally 10 
tracheids. | 
1-20 cells. 
_4 [ mostly | 
1-4 ] | 
1-2. 
Round, large, ori- 
fice oval, never | 
extending beyond | 
border. 
Not numerous, 
Zonate ; 
from middle of ring | 
to a limit of 20 | 
tracheids from 
outer limit of 
growth-ring. 
