Collins and Kempton: Patrogenesis 
the succeeding internodes, was closed 
and solid, consequently the growth of the 
plant terminated with the first leaf. 
During the early stages the remaining 
six plants all behaved much.as did the 
first generation plant, the only observ- 
able difference being their more early 
branching and the fact that the branches 
were nearly prostrate for several months. 
Studies of Tripsacum seedlings dis- 
closed no such tendency.to produce 
horizontal branches from the lower 
nodes. Minor differences in the devel- 
opment and distribution of the hairs 
appeared, but these were not consistent 
even among the plants having the 
same male parents. 
As the plants developed the diversity 
became more pronounced, although the 
variations were largely in the nature of 
abnormalities. With one exception the 
main axes of all the plants terminated 
their growth much earlier than is 
customary in Durango Euchlaena, only 
ten to fourteen internodes being pro- 
duced. The branches from the lower 
nodes of all these plants greatly exceeded 
the main stalk in height and produced 
many more internodes. The exception 
noted was one of the plants having the 
Liberian maize for male parent. This 
plant produced 51 internodes, a larger 
number than has been recorded in 
Euchlaena, Tripsacum or maize. 
The terminal inflorescence of these 
six second generation plants varied 
greatly, but none of the forms showed 
any approach to Tripsacum. One of 
the most striking abnormalities con- 
sisted in the replacement of the lower 
spikelets of the terminal inflorescence 
by little plants? This abnormality 
occurred in the plant having the 
Florida Euchlaena for its male parent, 
in two of the second generation plants 
obtained by self-fertilization, and to a 
less extent in one of the plants having 
the Liberian maize for male parent. 
Several of these little plants which 
developed roots while still attached to 
the parent were removed and potted. 
They grew into plants resembling the 
larger branches or suckers of the 
parent plants and matured seed. Plants 
3A similar abnormality has been observed in maize. 
Cont. U. S. Nat. Herb., XII, Pt. 10, pp. 453-455, 1909. 
Maize Plant. 
109 
from some of the seed thus produced 
were grown during the past season 
(1915) and behaved like plants from 
self-pollinated seed of the second genera- 
tion plants. 
The diversities of the first lot of 
second generation plants, together with 
the occurrence of hitherto unobserved 
abnormalities, led us at that time to 
believe that although we could detect 
to indication of Tripsacum characters, 
the plants were something other than 
pure Euchlaena. 
Further plantings from the original 
lots of seed secured from the first genera- 
tion plant were made in the greenhouse 
in April, 1914. As soon as the weather 
permitted these were transplanted to 
the open and still other plantings were 
made directly in the open soil. We thus 
had second generation plants maturing 
in the greenhouse and others in the 
early stages growing in the open at the 
same time. 
These later plantings, including both 
those transplanted and those planted 
in the open, developed none of the 
abnormalities observed in the first lot 
grown in the greenhouse. The straight 
second generation plants appeared to be 
pure Durango Euchlaena. The others 
were what might have been expected 
in first generation hybrids between 
Durango Euchlaena and the different 
types of maize used as male parents. 
THIRD GENERATION 
In the season of 1915 experiments 
were conducted near San Diego, Cal. 
The long growing season of Southern 
California afforded the first opportunity 
to allow plants of the hybrid to grow to 
maturity undisturbed. Small plantings 
were made of such second generation 
seed as had been obtained and the 
following plants were secured: ten plants 
from self-pollinated seed of three second 
generation plants of the hybrid; seven- 
teen plants from self-pollinated seed of 
three plants of (Tripsacum x Euchlaena) 
X Liberian maize; five plants from 
self-pollinated seed cf one plant of 
(Tripsacum x Euchlaena) X Florida 
Euchlaena. Plantings of Durango 
See Collins, G. N., Apogamy in the 
