35 
appears to be fully justified by the following statement quoted 
from a letter dated December 24, 1921, from the general man- 
ager: 
"Your letter of the 23rd with enclosure, Rule V, pertaining 
to the protection of the watershed area at the head of Palolo 
and Manoa Valleys received, for which I thank you. In reply 
would say that T am heartily in accord with the stand you have 
taken and the means you have adopted to accomplish the end. 
This department has had considerable trouble in Palolo Valley; 
hundreds of trampers visiting this valley every month, and some 
have entered the tunnel, the men working there protesting, but 
to no avail." 
On mainland city watersheds every possible precaution is tak- 
en to keep pathogenic bacteria out of the water and one of the 
rules most strictly enforced is the exclusion of humans from 
city watershed areas. The city of Portland, Oregon, for exam- 
])le, has the Bull Run Reserve set aside for this specific purpose. 
It embraces an area in the Cascade Mountains of 19b square 
miles and all persons, with the exception of forest rangers and 
water works employees while in the pursuit of their duties, are 
strictly prohibited from trespassing on the watershed. The j\Iaza- 
mas and other tramping organizations in the region are glad to 
kokua this rule. The city "of Seattle with its Cedar River water- 
shed and San Francisco with its Spring Valley watershed have 
similar prohibited areas. 
Susceptibility of Hawaiian Forest. 
The native forest, including the ground cover, on our own 
city watershed is of such a sensitive nature as to be far more 
susceptible to damage by human agency than are the coniferous 
and hardwood forests on the city watershed areas mentioned 
above. The latter consist of vigorous, deep rooted trees, which 
every autumn must harden themselves naturally for a more or less 
vigorous winter season. Such trees grow in more open stands 
and can exist independently of the dense ground cover of ferns 
and shrubs for the protection of their root systems which is 
so essential for the healthy existence of the delicate indigenous 
Hawaiian forest. 
Only those who are keen observers who have spent long hours 
in our woods, and have studied our Hawaiian forests from the 
pathological and silvical viewpoint, fully realize that the indi- 
genous forest in these islands is an extremely delicate and com- 
plicated afifair which reacts promptly to any outside interference. 
One who was ably qualified to understand the station, Mr. A. 
Gartley, wrote me on March 21, 1919, as follows: 
'T have noticed recently in the papers that there is consider- 
able agitation by the Trail and Mountain Club to reopen the 
