206 CALIFORNIA ACADEMY OF SCIENCES [Proc. ATH SER. 
BOTANICAL REGIONS 
Those who have written on the phytogeography of the Gala- 
pagos Islands in the past, have often mentioned the great 
difference in the character of the vegetation on the higher and 
lower parts of many of the islands, a difference that is very 
marked and can often be readily seen at a mere glance from 
the shore or a few miles out at sea by the contrast in the color 
of the vegetation in the several regions. In fact it is often 
easier to make out the limits of the regions from a distance 
than close at hand, for they frequently grade imperceptibly 
into each other, and the variations in color can not be so readily 
distinguished when one is going through the islands. On 
certain islands some of the regions are often ill defined or 
entirely lacking, a fact that is probably due mostly to climatic 
but sometimes to edaphic factors. 
Above the strand vegetation, which forms a narrow belt 
along the shores in many places, four botanical regions can 
be recognized, the Dry, Transition, Moist, and Grassy. 
Dry Region 
The lower slopes of the higher islands and the whole slopes 
of the lower ones are covered with a vegetation which is very 
xerophytic in character. The most striking plants in this 
region are the arborescent cacti, which often occur in large 
numbers and sometimes attain a height of forty or more feet. 
Except the cacti, the trees in this region are for the most part 
rather low, deciduous in character, and very much scattered. 
Between the trees, where they occur, the ground is usually 
covered with low bushes, which either shed or greatly reduce 
their leaves during the greater part of the year, and those 
which retain their leaves usually have them covered with a 
heavy coating of plant hairs. The landscape accordingly pre- 
sents a dreary gray aspect, which is greatly accentuated by 
the color of the trunks of both the Croton bushes and Bursera 
trees. ; 
During the spring months this region takes on a green 
appearance, but is lighter in color than the moist region above. 
During this season most of the annual plants spring up rapidly, 
and mature before the dry season sets in again. 
