xxviii 
BOTANY. 
was noticed in a dead branch, eight inches in diameter, apparently of Pinus 
monophyllay found in the East Humboklt Mountains. Here the decay of the 
bark and drying of the wood revealed very plainly the course of the fibres, 
which in a length of seven feet made four complete circuits. In some por- 
tions the direction was very nearly at right angles to the axis of the branch, 
and the length of the outer series of fibres must have been at least ten feet. 
An opportunity was offered at the saw-mill in Euby Valley of ascer- 
taining the age and dimensions of several specimens of Pinus Jlexilis from the 
upper canons of the East Humboldt Mountains. The following table gives 
the length and end-dimensions of the ''cuts," and the width of each series of 
fifly rings from the outside toward the center. A comparison of these last 
measurements shows great uniformity of growth in the different periods, in- 
dicating a hke uniformity in the conditions of temperature and moisture. To 
these arc added a few measurements of Artemisia tridentata and Purshia, 
also made in Ruby Valley, besides which may be mentioned a Juniperus 
occidentalis twelve inches in diameter with 250 rings and a Cercocarpus ledi- 
foUus about two feet in diameter with 160 rings. 
Measurements of Tree and Shrub Grcnoth. 
Pinus flexilis. 
Artemisia 
tridentata. 
Purshia 
tridentata. 
Number of rings. 
)-< 
3 
O 
O 
ti 
c 
u 
►J 
Larger diameti 
Smaller diameU 
'3 . 
2 
0 c 
•S *! 
Second. 
Third. 
Fourth. 
Fifth, 
Sixth. 
Seventh. 
Eighth. 
Remainder. 
Diameter. 
Rings. 
Diameter. 
Rings. 
Feet. 
In. 
In. 
In. 
In. 
In. 
In. 
In. 
In. 
In. 
In. 
In. 
In. 
In. 
12. 
26. 
22. 
486 
•7 
1 .0 
1.0 
^•3 
I . I 
1.0 
1.9 
1.6 
3-4 
8.0 
6S + 
4-3 
36 
19. 
26. 
13-5 
462 
1,0 
I.O 
^•25 
1-5 
1.2 
1.0 
-9 
2.25 
2.9 
5-5 
S8 
3-0 
61 
12.5 
30-5 
22. 
444 
•75 
1 .0 
1 .0 
1-5 
i.i 
1.2 
2.6 
3-7 
2.4 
4-5 
35 
37 
38 
14. 
30. 
22. 
400 
1-3 
1-7 
i'5 
2.4 
2.6 
3-1 
1.4 
1.0 
4.0 
6. 
19. 
14. 
400 
•75 
•75 
1.0 
•7 
1. 1 
i-S 
3.0 
1-7 
2.0 
3-0 
7- 
34- 
32. 
357 
1.8 
1.8 
2.1 
2.0 
2.1 
3-6 
.6 
2-5 
19 
IS 
10. 
16. 
II. 
233 
1.6 
1.8 
2.0 
1-5 
I.I 
= •5 
When the canons in the mountains are dry the vegetation in them differs 
little from that of the intervening ridges, but in the presence of moisture 
and especially upon the sides of the higher canons there is frequently a con- 
siderable amount of shrubby or perennial herbaceous growth. The most 
common species are Ceanothus velutinus, forming dense and tangled patches at 
an altitude of from 7,000 to 9,000 feet, Ribes cereum scattered over all the 
