298 
Journal of Agricultural Research 
Vol. I, No. 4 
The three types of maize used in the box experiment were also planted 
in the field. Four seeds of each of the varieties were planted as follows:: 
At the surface and at 5, 10, 20, 30, and 40 cm, below the surface. 
The greatest depth from which plants of the Chinese variety reached the 
surface was 10 cm., that of the Boone County White was 20 cm., 
while that of the Navajo was 30 cm. 
The seeds planted at the surface were naturally the first to appear, 
but on June 17, one month after planting, the largest of the Chinese 
variety were those from a depth of 5 cm., while the largest plants 
of both the Boone County White and the Navajo maize were from the 
10-cm. depth. On July 11 the plants that came up from a depth 
of 10 cm. were the tallest in all the varieties, including the Chinese, 
and to the end of the season this appeared the most favorable depth for 
the Chinese and Boone County White varieties. With the Navajo, 
however, the plants from a depth of 20 cm. had equaled those from the 
10-cm. depth before the end of July, and from that time the plants from 
the 20-cm. planting continued to make the most rapid growth, as 
though this depth represented the most favorable condition for the 
Navajo variety. 
DESCRIPTION OF ROOT SYSTEM 
We have observed further that the root systems of the Navajo, Hopi,, 
and Zuni varieties differ from those of the other varieties; the roots 
of their seedlings extend to a greater depth, and there is only a single 
root arising from each seed, while in the seedlings of the Chinese and 
Boone County White varieties the roots are shorter and more numerous. 
The roots of maize are of two kinds: Those that arise from the embryo 
or seed, called “seminal roots,” and those produced from the nodes of the 
plant. Of the latter class those that arise from the nodes above the 
ground are often called “brace roots” or “aerial roots.” In the varieties 
commonly grown in the United States there are, in addition to the pri¬ 
mary root, or radicle, from two to six additional roots that arise from the 
base of the cotyledon. These secondary seminal roots, though appearing 
somewhat later, usually equal or exceed the radicle in size. In the 
Pueblo varieties of maize these secondary seminal roots have been absent 
in all seedlings thus far examined, the radicle being the only root arising 
from the seed. (See Pis. XXIX and XXX, fig. 2.) 
FIELD STUDIES OF PUEBLO VARIETIES OF MAIZE 
In September, 1913, opportunity was afforded for a visit to the Zuni,. 
Navajo, and Hopi Indian Reservations of Arizona and New Mexico. It 
was thus possible to form some idea of the agricultural significance of the 
peculiar habits of germination of this type of maize. 
The value of deep planting made possible by the greatly elongated 
mesocotyl was obvious. In the localities selected by the Indians for 
