XIX IN THE ECUADOREAN ANDES 213 
RiOBAMBA, iVf^Z/. 2, 1858. 
. . . Since I last wrote to you I have several 
times done the 40 miles from Ambato to Riobamba 
in one day, and the distance begins to seem much less 
than at first. But my back is just now aching con- 
siderably from having ridden 112 miles in three 
days, for the most part along steep and dangerous 
declivities. I left Quito in September and came 
straight on to Riobamba, and then 60 miles farther, 
in a south-westerly direction, crossing the summit 
of the Cordillera at an elevation of 12,500 feet, and 
then descending to the valley of Pallatanga at 5000 
to 6000 feet. This pass, called the Paramo de 
Naba, is far lower than that over the shoulder of 
Chimborazo (14,000 feet) on the way from Quito 
and Ambato to Guayaquil. I scarcely suffered 
from the cold on Naba, although I was buffeted 
by a hail-storm ; and I gathered there some very 
interesting plants, including the beautiful Gentiana 
cernua found by Humboldt and Bonpland on Chim- 
borazo. It is great pity that these fine Andine 
Gentians have proved so difficult to cultivate in 
England. Anderson, the famous nurseryman of 
Edinburgh, has succeeded in raising a great many 
plants of the Andes, from seeds sent to him by 
Professor Jameson of Quito, but I am told that 
none of the Gentians have survived. It is difficult 
to imitate the conditions of their growth ; for some 
of them endure frost nearly every night of their 
lives, yet so light is the pressure of air upon them 
that the frost injures them not ; yet they die when 
frozen in the dense atmosphere of the plains. I 
have seen epiphytal Orchids — Oncidiums, Odonto- 
