84 PITTONIA. 
number of native Californian plants. The peculiar character 
of the unquestionably introdueed part of the San Miguel 
flora signifies so much that I will repeat it in connection with 
two other correlative facts: Point Conception and this island 
form a southern limit, seaward at least, to the general phyto- 
graphic region of northern and central California: the north- 
ern and southern portions of the state have respectively their 
own naturalized foreign as well as native vegetation: the 
naturalized plants of San Miguel are actually (what we should 
expect them to be) those of the northern, not southern 
division of the mainland. This mesembrianthemum can not 
have reached the island from the northward, for it does not 
grow there now and there is no evidence that it ever did. It 
is not probable that it came from the mainland lying south- 
eastward, for there are neither the winds nor the ocean cur- . 
rents to have brought it, the two climates are very dissimilar, 
and other more common and more migratory species of 
southern California have failed to come and plant themselves. 
The conclusion is fair, and even hard to avoid, that the species 
is indigenous to San Miguel. Its other native habitat is, as I 
have said, South Africa. And it may just as well be indige- 
nous both there and here as may the lavateras of our islands 
find generic kindred nowhere in continental America north or 
south, but only in far off Australia and on the shores, still 
more remote, of the Mediterranean Sea. 
The list of species is about as full as could be made so late 
in the year as September. The time given to the actual work 
of exploration was two weeks; and this, for a piece of terri- 
tory at once so limited and so free from obstacles to pedestrian 
travel, was enough for a somewhat thorough canvass of the 
vegetation in so far as visible at that time of the year. But 
no doubt an equal number of days in April or May as actively 
devoted to research would considerably extend the list, a large 
proportion of the species being annual, and many such pre- 
sumably so delieate as to have disappeared entirely, weeks or 
months before my seareh began. Of small perennials too, 
such as are vernal only in their flowering, —alliums, saxifrages 
