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carry only the merest traces of moisture. Throughout most of 
this heavily watered region, the vegetation is of the densest char¬ 
acter. Allowing for the breaks caused by the streams, it might 
be said that an arboreal animal, ascending a tree upon the An¬ 
dean foothills, could pass to the Atlantic without once descending 
to the ground. 
The species and genera of this eastern Andean region have 
in general a very wide range. With the latitude, varies the alti¬ 
tude at which they grow. As we pass to the cooler southern 
region, a species or its representative creeps down upon the 
mountain sides. Thus, the Desfontainea spinosa, Remy., which 
I collected abundantly in northern Bolivia, gradually descends, 
until in the neighborhood of the cape, Lieutenant Safiford finds 
it near the sea level, constituting a characteristic feature of the 
landscape. Sometimes also, a species has its limits as to altitude 
very narrowly and sharply defined, but will be represented at 
successively lower elevations by other species exceedingly closely 
related. Of this, the Cinchonas furnish us a striking example. 
Each altitude has its own species—if species they can be called— 
and they usually overlap to but a trifling extent. I have (in 
two cases) looked along a mountain side where miles of Cinchona 
Calisaya had been planted, and seen the upward limit defined to 
within fifty feet by a line of dead or dying trees. 
In general, we are disappointed by the scarcity of flowers as 
compared with the abundance of plants. To this rule, trees and 
many herbs are exceptions. But in the case of shrubs and vines, 
of which latter there is everywhere a multitude, it is strikingly 
true. It is probably to be accounted for by the steepness of the 
land and a climate highly favorable for the reestablishment of de¬ 
tached fragments, torn away and carried to a new position. Un¬ 
able to obtain the light and air necessary for a high floral de¬ 
velopment, they have learned to depend upon a less complicated 
method. 
Turning to the western side, we find, as stated, a region in 
which almost every condition is reversed. With more or less 
scanty rains, strictly limited to a few months or even weeks, we 
get a treeless and almost shrubless region, with a temperature 
subject to very sudden and great variations. The amount of 
