224 The Flora of Guadalupe Island. [ April, 
they demonstrate a connection between the island and California, 
yet they also indicate that that connection has been only at a re- 
mote period, and that their participation in the introduction of 
plants must have been slight. 
It might therefore be conjectured, if the island were of com- 
paratively recent formation and always disconnected from the 
main-land, that its flora would show a meagre list of species almost 
wholly Californian. Or if, on the other hand, it had at some 
time been connected with the continent, that then its vegetation 
would be similar to that of the adjacent peninsula, unless some 
counteracting influence should have been at work, as -would seem 
to be true of the birds. 
To show to what extent the flora of Lower California differs 
from that of California proper, reference may be made to the list 
of plants collected by Xantus at the lower extremity of the pe- 
ninsula,! as given by Dr. Gray in the sixth volume of the Pro- 
ceedings of this Academy. Of the one hundred and eighteen phe- 
nogamic species there enumerated, only six are probably found 
even in extreme Southern California, while thirty others range 
northward only as far as Sonora, or eastward through Mexico to 
New Mexico or Texas, the remainder being peculiar to the pe- 
ninsula or exclusively Mexican. The peninsula shares in this 
difference with Mexico itself, the type of whose whole flora ac- 
cords rather with that of the eastern portion of the continent 
northward, except so far as it would necessarily be affected by 
the more tropical character of the climate. Of this a good and 
sufficient illustration is seen in the fact that of the Phascolew, a 
tribe which is well represented in all the Atlantic States, Texas, 
Southern New Mexico, Eastern Arizona, Sonora, Lower Califor- 
nia, and all of Mexico southward, not one species is found within 
the limits of California, nor in the interior basin west of the 
Rocky Mountains. 
The only collection that we have of the plants of Guadalupe is 
that made by Dr. Edward Palmer during the last season, from 
February to May, which is probably as complete as was possible, 
though attended with much labor and difficulty. He visited all 
parts of the island, often finding it necessary to reach places which 
the goats had found inaccessible, in order by means of ropes an 
poles to secure rare specimens of species which appeared to have 
1 The island of Guadalupe is equally distant from San Francisco and Cape San 
Lucas, but three degrees of latitude nearer to the latter point; and the difference of 
latitude between the cape and San Diego is little greater than that between Guada- 
lupe and San Francisco, 
