Collins and Kempton: Patrogenesis 
Euchlaena were also made for compar- 
ison. The seed was planted on March 
16, and a second planting of Durango 
Euchlaena was made on June 11. The 
third generation plants of the cross, 
with the exception of those that had 
been crossed with maize, all developed 
as normal Durango Euchlaena, free 
from any of the abnormalities observed 
in the second generation plants grown 
in the greenhouse. Early in the season 
the branches showed the prostrate habit 
characteristic of the first and second 
generation plants, but the Durango 
Euchlaena plants also showed the same 
habit. Curiously enough, the first 
planting of Durango Euchlaena devel- 
oped a series of abnormalities almost 
exactly paralleling those of the second 
generation hybrid plants grown in the 
greenhouse. Of eighteen Durango 
Euchlaena plants, twelve produced 
aborted main stalks that matured with 
nine to thirteen leaves. Four of the 
eighteen plants produced apogamous 
plants in the place of spikelets. All of 
the abnormal plants produced numerous 
suckers that grew normally and were 
indistinguishable from the main stalks 
of normal Durango Euchlaena plants. 
The later planting of Durango Euch- 
laena was entirely free from these 
abnormalities. 
Table 1 gives the average measure- 
ments of plants grown at San Diego. 
It can be seen that there are no striking 
differences between the hybrid plants 
and the Durango Euchlaena, the hybrid 
113 
plants being in many particulars inter- 
mediate between the two plantings of 
Euchlaena. Where significant differ- 
ences occur they are not of a nature to 
suggest Tripsacum. 
Several hundred plants from open 
pollinated seed of the different second 
generation hybrid plants were also 
grown and carefully examined for indi- 
cations of Tripsacum, but no characters 
or abnormalities not attributable to 
Euchlaena or maize were observed. 
TRIPSACUM POLLINATED BY MAIZE. 
To repeat the original cross in the 
late plantings has been impossible, 
through a failure to bring Euchlaena 
and Tripsacum into flower at the same 
time. In 1914, however, maize pollen 
of several varieties was available at the 
time the Tripsacum plants were in 
flower. Numerous attempts to fer- 
tilize Tripsacum flowers with maize 
pollen resulted in a small quantity of 
viable seed. A number of plants from 
these seeds have been grown, but 
instead of resembling the male parent, 
all are apparently pure Tripsacum. 
These crosses were made with such 
precautions against accidental pollina- 
tions and have been secured in such 
numbers that there can be little doubt 
regarding the parentage of the plants. 
Euchlaena and maize are so nearly 
related and have behaved so much 
alike in the perjugate generations of 
our original cross with Tripsacum that 
we fully expect to secure similar results 
TABLE 1.—COMPARISON OF Two PLANTINGS OF DURANGO EUCHLAENA WITH TRIPSACUM X 
DURANGO EUCHLAENA, GROWN AT CHULA VisTA, CAL., 1915 
Durango Durango Tripsacum X 
Euchlaena Euchlaena Euchlaena 
planted planted third 
March 16 June 11 generation 
Pleo ie tn CEONbMMeLerS, 9) 40134. S55 <a vac | Re See 31320-76225). 202205 role ZO0K0 eS 
Exsertion of tassel in centimeters.............. 6.6+ .94 3.0 248 fee 4S 
Branching space in centimeters................ 139 =e ALS lise. 3 1 ORS reeon 
Length of central spike in centimeters ......... 13.8+ .84 10.6+ .44 8. 2==~ 323 
Length of lowest tassel branch in centimeters... 17.5+ .64 15eS-= vai 11 == Seo 
NOM Dian Chesmer eget anit ke ands Vana Wiles sii lee Jess y(oy2! 1S eee 
Ilo: Seceraye EVRTESE ay om eta eee an eee GO Sar lied 1 20RD 50 Dif Wee ANS 
Length of longest leaf in centimeters........... 0 sie= (0) 67.8=1.47 ifn eee Ate) 
Width of longest leaf in centimeters............ 4.24 .13 6,02 >.20 4.0+ .08 
Nodes above longest leaf.s.! 0.000... 2..0..0.. Ohyes 9 cals, 8. 8==r 739 10.3+ .66 
INI@ig SVE ees, Ne he i 18.8+ 1.48 bse 27/6 Lis ees 
Height of tallest sucker in centimeters..........300.0+10.10 195.0+2.79 199 0+ 10.90 
Nomexsertedminiternodes.... acs... 2.4-. 8s ieee 629 -=— eo (ozs A =o 
Diameter of stalk in centimeters............... = aT Oe teva le 2M} Seen shy 
