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here, above all places, it is essential for an assured water supply 
that the forest be maintained in a perfect condition. 
Let us consider what has happened here. A naturalist in- 
forms me that he visited Palolo Crater as far back as 1878 and 
that there certainly was no decadence of the forest at that time. 
"The Crater and its environs beyond were thickly covered with 
a healthy growth of trees and the ground cover was perfect." 
Dr. H. L. Lyon, Pathologist and Botanist of the H. S. P. A. 
Experiment Station, who has made careful observations of this 
region over a period covering the past 14 years, is of the opinion 
that the introduction of Hilo grass has been the cause of forest 
decline in this particular region. In ''The Hawaiian Planters' 
Record" of D'ecember, 1919, page 300, he writes as follows : 
"Probably no watersheds in these Islands are in a more crit- 
ical condition than those on Oahu, and certainly no water supply 
is of more vital importance to this Territory than that derived 
from these watersheds. 
"This Island has been more extensively and intensively ex- 
ploited than any other in the group, and, carrying as it does 
the bulk of the Territory's population, its forests have been sub- 
ject to more interference from man and animals than those of 
the other islands. 
"Cattle have been the greatest factor in pushing the forests 
back to their present narrow limits, and at certain vital points 
cattle are still allowed to penetrate the remaining forests. 
Where the cattle have been excluded the Hilo grass is keeping 
up a relentless attack, and little by little is pushing the forest 
line back towards the summits of the mountains. 
"A very serious injury has been done to these forests by the 
promiscuous cutting of trails. These trails have formed ave- 
nues for the entrance of Hilo grass which, at many points well 
within the forest, has taken possession of considerable areas. 
This is very noticeable around the crater at the head of Palolo 
Valley. Ten years ago this trail ran beneath large trees and was 
bordered by masses of delicate ferns. Now the trees are dead 
and for the most part fallen over; the delicate ferns have dis- 
appeared and the ground is completely covered with Hilo grass." 
At the very summit of the lesser Mt. Olympus peak where 
picnickers have been accustomed to stop for lunch during the 
past few years, and have brought in grass seed on their shoes, 
there is now, besides the blatant lunch papers, strings, orange 
peel and empty bottles, telltale of the untidy tramper, a patch of 
Hilo grass at least 12 feet square and not far oflf another patch 
still larger. There can be no question but that this grass has 
grown from seed brought up from the lower levels on the boots 
of trampers. It is not claimed that this grass carrying is done 
intentionally or maliciously; it is done all unconsciously by the 
innocent tramper who does not realize that the thousands of 
little white specks which cling to his boots are the seeds of a 
pernicious weed. It is impossible for anyone to go through 
