Peruvian Andes (83, 84), while N. Tabacum probably 
arose in a similar manner on the eastern slopes of the 
Andes, perhaps in the region of Northern Argentina 
(84, 88). The latter, at least, is not known from the wild 
state (85), and it or both may have arisen in cultivation. 
From their distribution at the time of European discov- 
ery, it would seem that N. rustica, which was then the 
cultivated tobacco of the eastern United States, was the 
first to be cultivated, or at least the first to be widely 
dispersed. N. Tabacum, arising or entering cultivation at 
a later date, was superior to the earlier species, especially 
at lower altitudes, and largely replaced it in South Amer- 
ica and parts of Middle America. The European cultures 
served to hasten the replacement of NM. rustica, and it is 
still peripheral in its distribution, being grown principally 
as a garden tobacco in the Old World. It may be that 
indigenous species of tobacco were early cultivated in 
Mexico, as they were in much of the western United 
States (182), and later replaced by the South American 
species. A monograph of Nicotiana, by Goodspeed, is in 
press and should be of interest. (88, 84*, 85-88, 98, 
177a, 182*, 190, 196a) 
Nopalea cochenillifera (L.) Salm-Dyck: Nopal 
nochezth, 
A cactus similar to Opuntia in aspect, this species is 
well known as the plant on which the early Mexicans 
cultivated the cochineal insect, the source of a highly 
valued red dye (26). This cactus is spineless, apparently 
the result of selection under cultivation. ‘This species of 
Nopalea is probably native to some part of southern 
Mexico. The present cultivation of cochineal in Oaxaca 
is said to utilize varieties of Opuntia ficus-indica. (24, 
26*, 49, 68, 93, 158, 191*) 
[ 1389 ] 
