ae 454 , Structiral'n and : Physiological Botany. 
carried on in detached spots. Even the higher portigae of 
Guttiferee, Scitamimeze, and especially the most important — ‘ae 
and the thickets and thin woods which occur in the provinces — 
_New Mexico. The nature of ‘the vegetation is here deter- 
of the rainfall takes place in the form of ‘dudes thunde 
-Storms, while at other times the air 1s ee ony fe 
the coast-range, as well as the Puna district, are treeless, but - 
are covered with an Alpine herbaceous and shrubby vegeta- 
tion. A richer tropical vegetation is to be met with ey thee | 
Peruvian Andes only on thé eastern slope of the eastern _ 
Cordilleras, or in the valleys which intersect the Puna bs) 
district with deep rocky channels, and lead to the lowlands — q 
and the sea. A long rainy season in summer is here a 
source of inexhaustible fertility ; coffee, the plantain, sugar- a4 
cane, and cocoa, are the cultivated crops. While the — 
botanical features of the district at the foot of the Cordilleras. 4 4 
and in the deep valleys, merge gradually into those of the 
Brazilian flora, the upper belt of woods, the Ceja of the 
Montafia, present some peculiar features, tree-ferns, palms, — ¥ q 
ae 
of all, the Czzchona or Peruvian bark. a 
21. Lhe Pampas Region. Dist 
By a Pampas is meant a treeless pasture-land covered. 
with grass ; but in the region of vegetation so designated 
must be included the whole country extending from the — 
boundary of Brazil, where the regular rainy seasons of the 
tropical zone cease, across the States of La Plata and Pata- 
gonia nearly to the southern extremity of the Srna 
The true pampas resembles the grass plains on the Missouri; — 
of La Plata lying nearer to the southern limit of the tropic, — 
resemble the chaparals or mesquit-thickets of Texas and | 
mined by the distribution of the moisture ; the greater part. 
- 
