82 REPORT OF THE CALIFORNIA EARTHQUAKE COMMISSION. 
water to land along his water-front. Dr. Southworth has found the navigation improved 
at various places in the eastern part of the lagoon, the water being deeper than formerly 
for the same normal state of the tide, and this observation is confirmed, by Mr, Morse, 
who now at high tide sails over a portion of McKennan Island which could not formerly 
be crost with a boat. Various residents are of opinion that the sand-spit, except at its 
extreme western end, is lower than formerly. A lady who has lived at Dipsea Inn several 
years states that before the earthquake the spit was overtopt by waves only during 
storms with heavy winds, but that since the earthquake waves frequently wash over it. 
Yt will be observed that all this testimony, with the single exception of Mr. Morse’s 
observation of water-levels near his house, tends to show a general sinking of the land 
east of the fault, and a general rising of that to west of it. 
Professor Kofoid, in seeking evidence from the distribution of marine life, found the 
barnacle the most available form. It is abundant at many places; its shell remains as a 
witness after the death of the animal, and its upward limit bears, at many places, a 
definite relation to the line of high tide. The best places found for observation were 
certain groups of piles at Bolinas and along the northeast shore of the lagoon. From a 
study of these localities it appeared that in the upper part of the barnacle zone the per- 
centage of dead shells is notably greater on the west side of the fault than on the east 
side, but there is not a well-marked zone of dead barnacles on the west side, nor is there 
a zone of exclusive young barnacles on the east side. The evidence thus gives a qualified 
support to the theory of elevation and subsidence. Outside the lagoon, on the open 
sea-front, the upper limit of barnacles is too indefinite and irregular to be available for 
a study of this character. 
Visiting Pepper Island in company with Professor Holway, I found the position of 
the fault-trace clearly indicated by a difference in the color of the vegetation. The island 
is low, only a narrow strip at the south remaining above water at ordinary high tide, 
and from this strip there is a gentle slope toward the north and northwest. The vegeta- 
tion on the highest part is somewhat varied, but the lower slopes are occupied almost 
wholly by a single species of Salicornia (pickle-weed). This is locally the lowest lying 
of the shore forms, and it descends the slope to a somewhat definite line beyond which 
the mud is bare. It is evident, therefore, that its lower limit is determined purely by 
physical conditions and not at all by the competition of other plants. It is thus pecul- 
iarly sensitive to changes in the relation of land to water. West of the fault a broad 
area covered by this plant presented, at the time of the visit, a brownish-green color, 
while the adjacent areas east of the fault had a dull brown color. The contrast was so 
strong that the eye could readily trace the line of the fault. We found also that the 
ground east of the fault was, in general, lower than the ground at the west, and I after- 
ward made a series of measurements showing the average difference in elevation to be 
12 inches. 
Pepper Island was subsequently examined by Professor Jepson, who not only traced 
the brown color of the Salicornia to an abundance of dead and dying plants, but found 
considerable corroborative evidence in the condition of other species living at slightly 
higher levels. On McKennan Island a similar condition was found. The island is girt 
by a zone of Salicornia, the outer or lower belt of which was found to be brown. A single 
measurement of the vertical range of dead and dying plants gave 10 inches. 
The northeastern shore of the lagoon was examined for evidence of similar character, 
but the result was less satisfactory. The lowest plant growth is not everywhere the 
same and the local conditions are materially different. The slope is less gradual, the 
soil is more gravelly, and there is deposition of detritus eroded from the land by streams 
and waves. At some points a belt of plants at the extreme limit appeared to be suffer- 
