terminally and without a tassel. The internode pattern 
of normal plants of Trichachne follows that of ordinary 
grasses; the pattern of plants with the lateral ‘‘ear’’ and 
a terminal inflorescence follows that of the usual maize 
plant, and the pattern of plants with the terminal ‘‘ear’’ 
closely adheres to the pattern established by maize plants 
with terminal ears. The ‘‘ear’’ in Trichachne is a fascia- 
tion in which longitudinal growth is halted so that the 
inflorescence is enclosed by the leaves of the culm on 
which it is borne. It is significant that anthers do not 
develop in the ‘‘ears’’ although some of the seeds are 
nearly normal in size and apparently variable. Trichachne 
has been collected in both the fasciated and ordinary form 
in Jamaica, Surinam, Bolivia and the states of Ceara, 
Baia, Goiaz and Mato Groso in Brazil. Detailed infor- 
mation upon it will be presented in a later paper. 
Maize in South America may be considered as influ- 
enced by three tendencies which may be termed Tripsa- 
coid, Andropogonoid, and fasciated. Mangelsdorf and 
Reeves (1939) have postulated that there is some Trip- 
sacum influence in North American maize, and suggested 
that some South American maize in the Andean region 
is also contaminated, but to a lesser degree. Further 
evidence supports this theory. The similarity of much 
lowland maize, especially that of Paraguay and Bolivia, 
to segregates from maize-teosinte crosses ; the occurrence 
of Tripsacum australe Cutler and Anderson, a species 
without terminal chromosome knobs (Graner and Addi- 
son 1944); and morphological similarities between 7’. 
australe and some of the South American varieties of 
Zea suggest two possibilities. Either there is consider- 
able Tripsacum contamination which cannot be correlated 
with chromosome knobs or some types of South Amer- 
ican maize show resemblance to Tripsacum because they 
are not distantly removed from it. The great diversity 
[ 2638 ] 
