Robinson and Greenman—Galapagos Flora. 135 
Art. XVII.—Contributions from the Gray Herbarium of 
Harvard University, New Series, No. IX; by B. L 
Rosinson and J. M. GREENMAN. 
I. On the Flora of the Galapagos Islands, as shown by the 
| collection of Dr. G. Baur. 
W38ILE exploring the Galapagos Archipelago in the summer 
of 1891, Dr. George Baur secured, besides zodlogical specimens, 
a large collection of plants. The latter have recently been 
determined at the Gray Herbarium and for various reasons 
possess considerable interest. They furnish in several cases 
more copious material of hitherto imperfectly known forms 
and, as is to be expected, contain a certain number of new 
species. Furthermore Dr. Baur visited not only all the islands 
hitherto explored but extended his collecting to no less than 
eight others, from which, so far as can be learned, no plants 
have been secured, or at least reported. It is well known not 
only that the archipelago possesses a peculiar and remarkable 
vegetation, but that the different islands exhibit in their floras 
a striking individuality. It has been accordingly a matter of 
interest to compare the forms of the newly explored islands 
with those of the others for some time known through the col- 
lections of Darwin, Edmonstone, Macre, Douglas, Scouler, 
Andersson and Agassiz. 
While upon some of the smaller islands Dr. Baur collected 
only afew species, enough material is at hand not merely to con- 
firm strongly the view that almost every island has its peculiar 
species and varieties, but to show clearly that even plants, 
which must pass as the same species, often exhibit, when found 
upon several islands, more or less striking racial differences. 
These facts, while in other respects noteworthy, derive a special 
interest from their relation to the probable origin of the flora 
of the group. Regarding the fauna Dr. Baur has in several 
recent articles called attention to peculiar harmonic relations 
existing between the forms of the different islands, and has 
argued from zoological grounds that the islands must at one 
time have been united, not only with each other but with the 
mainland near Central America. This view has been severely 
criticised by several writers, but no one has attempted to 
account for the peculiar distribution of differing, yet closely 
related forms upon the islands, and as the subject is one which 
merits further attention, it seems worth while to present the 
botanical data in some detail. 
Perhaps no species to be found upon the different islands 
better illustrates the noteworthy racial divergence in related 
