78 ERYTHEA. 
of other work at Berkeley which could not be deferred pre- 
cluded the possibility of its being undertaken by the present 
writer until the year 1891. However, the date of the com- 
pletion of the Observatory, and of the consequent occupancy of 
the station by residents, would certainly have been found too 
late for the recording of the earliest arrivals in the line of 
immigrant plants. Some of these must have come perhaps 
ten years earlier, along with the workmen and their teams, 
when the foundations of the Observatory were being prepared 
and the roads made. This earliest work must have involved 
the importation of provisions, grain and hay to the mountain 
top, while at the same time the digging and grading prepared 
places of germination for such seeds of alien plants as thus 
found their way to the locality. 
In the second place, Mount Hamilton having been chosen 
as the site of the Lick Observatory on account of its being a 
fair weather mountain, as compared with other middle Cali- 
fornian summits of equal or nearly equal elevation, it must 
be interesting to note how well the native vegetation, as com- 
pared with that of the other summits referred to, would have 
indicated to the botanist without other data, the relative 
immunity of this mountain top from fogs and long continued 
rains. 
The subjoined catalogue, embracing about two hundred 
and ten species of phanerogramic growths, besides several 
ferns, is not likely to prove a complete list for the limited 
and not very definitely cireumscribed area which it is meant 
to cover. It is drawn chiefly from field notes made by the 
writer during the last week of July, 1891; that is to say, in 
the midst of the dry season of the year, at a time when the 
greater proportion of annual species—and these form the 
great bulk of the native vegetation in all parts of California—. 
were long past flowering and quite dead. Owing to this 
circumstance, no doubt a considerable number of species 
must have escaped notice entirely; and some of those accred- 
ited were seen only in the herbarium of Miss Mildred 
Holden, as having been collected by her in June. Some 
