61 
The minor features of classification, below tribes and 
above varieties are color of kernels and cob, the shape of 
the kernels as expressed by their effects in forming sulci or 
otherwise between the rows, a scalloped or flat appearance 
to the circumference of the ear in section, etc. 
The variety characteristics are size of ear, more particular 
description of form, number of rows, more particular de- 
scriptions of shape and color of kernel, etc. 
So far as my collections allow of generalization, Tribe I 
is a northern form, or a form of cool regions, as it is of 
most general occurrence in the northern limit, or the more 
elevated limit of the agricultural species. Tribe IT is an in- 
termediate climate, or temperate form, while Tribe III 
occurs oftenest in the regions of hot and long summers. 
In the Races likewise the same fact seems established: 
Race A being largely northern, Race B mostly temperate, 
and Race C being more tropical. Whatever exceptions may 
appears to this generalization can be usually satisfactorily 
explained by the study of the local conditions which appear 
from the history of the sample. 
In the generalizations concerning the Agricultural Species, 
as founded upon our collections and historical records, we 
must call Zea * indurata, or flints, the most northern, 
although probably had circumstances justified the growing, 
Zea * everta, the pops, could occupy this position. The 
first * species has been received from Quebec, our highest 
northing, and was the kind almost or probably altogether 
exclusively grown by the New England Indians, although 
probably grown also by the Indians of the midland and 
more southern coast regions, as also in places in the Middle 
States, and further south, extending to South America. 
The historical references for this statement are rather ob- 
scure, but the Indian derived words, Samp and Hominy, 
indicate flint corn, and flint corns are now found which 
traditionally have come from the Indians, or are at present 
grown by the Indians, as by the Tarahuamarers of Mexico 
in our collections. It may be obscurely identified in the 
early writers on Peru and Paraguay, and in the figures of 
the botanists of the sixteenth and seventeenth centuries. 
Zea * indentata, the dents, has a few forms which can be 
described as northern temperate, the furtherest point north- 
ward represented in my collections being Ogdensburg, N. 
Y., where the climate is modified by the geographical sur- 
roundings. As a rule, however, this * species cannot be 
grown successfully in New York, except in favored locali- 
ties. In the Middle West it is the predominant form, and 
furnishes the larger portion of our corn for export. It is 
now cultivated by the Indians of Northern Mexico, as 
