28 
Journal oj Agricultural Research 
Vol. XXX, No. 1 
The plants grown at Akron in 1921 
were packed in boxes and mailed to 
Manhattan, where the material from 
both stations was described. 
EXPERIMENTAL RESULTS 
About 60,000 kernels were examined 
in the course of this study, but space 
will not permit the inclusion of more 
than the summary tables of the results 
obtained. The data will be discussed 
for each character separately. The 
five characters are spikelet disarticula¬ 
tion, floret disjunction, basal hairs, 
awns, and lemma color, as described 
under experimental methods. 
SPIKELET DISARTICULATION 
The disarticulation of the spikelet 
from the lower segment of the rachilla 
is one of the fundamental characters in 
classifying oats. In this study dis¬ 
articulation was described as resulting 
from “abscission,” “semiabscission,” 
or “fracture.” Kernels having a clean, 
sharp separation with a prominent 
basal cavity with calloused margins, as 
found in Red Rustproof and other 
typical varieties of Avena byzantina, 
were described as disarticulating by 
abscission. This type of separation is 
illustrated in Plate 1, A. Those kernels 
having the characteristic roughish 
fracture and pointed base shown in 
Plate 1, C without smooth scaGr tissue 
or cavity, and generally associated with 
Avena sativa varieties such as Swedish 
Select were described as disarticulating 
by fracture. Kernels having a poorly 
or only partially developed basal cavity 
with rough tissue surrounding it were 
described as resulting from semiabscis¬ 
sion. A kernel having this basal form 
is shown in Plate 1, B. The results 
from the studies of 1920 and 1921 are 
presented separately. 
In selecting the original kernels from 
the bulk material preparatory to start¬ 
ing these experiments, only the two 
types, abscission and fracture, were 
chosen in any considerable number from 
any of the strains. A few kernels dis¬ 
articulating by semiabscission, how¬ 
ever, were sown at each station. At 
the Akron station so few kernels of the 
semiabscission class were selected in 
any of the strains, with the exception 
of Kansas No. 5211, that these few 
kernels were not classified separately 
but were included with those in which 
spikelet disarticulation was by abscis¬ 
sion. 
RESULTS IN 1920 
The detailed and summarized results 
of the study of spikelet disarticulation 
in 1920 are given in Table I. 
The data presented in Table I indi¬ 
cate significant differences among the 
strains. In only six strains at Man¬ 
hattan and in seven out of eight at 
Akron were parental kernels found 
which disarticulated by abscission. 
This clearly indicates that variation 
exists among different Burt oat strains 
with respect to this character. 
Kernels in which spikelet disarticu¬ 
lation resulted from abscission tend to 
produce progeny of the same type. 
Parental kernels described as disarticu¬ 
lating by fracture produced progeny 
of which about three-fourths disarticu¬ 
lated by fracture. Kernels in which 
spikelet disarticulation was classed as 
resulting from semiabscission were 
found in appreciable percentages in 
the progenies of all three parental 
classes. 
Kernels having the prominent basal 
cavity associated with abscission were 
found in the progeny of fracturing 
parental kernels, which have no cavity, 
in six strains at each station. Two 
strains, Kansas Nos. 5219 and 5220, 
at Manhattan, and one strain, Kansas 
No. 6004, at Akron, produced no 
kernels in which spikelet disarticu¬ 
lation was described as by fracture in 
the progenies of parental kernels dis¬ 
articulating by abscission and semi¬ 
abscission combined. 
The disarticulation resulting from 
fracture was very definitely inherited. 
At both stations, in all strains, with 
the exception of Kansas No. 6090 
grown at Akron, tlie parental kernels 
in which the spikelet disarticulation 
was described as fracture produced 
progeny of which 60 per cent or more 
was described as disarticulating by 
fracture. In general the results ob¬ 
tained show a rather strong correlation 
between parent and progeny in spike¬ 
let disarticulation. 
From the data in Table I it is evident 
that spikelet disarticulation is inherited 
in a definite manner. The summarized 
data indicate that there was a strong 
tendency for the kernels disarticulating 
by abscission and by fracture to trans¬ 
mit these characters to their progeny. 
The kernels in the class disarticulating 
by semiabscission tended to produce 
progeny almost equally divided among 
the three spikelet disarticulation types. 
RESULTS IN 1921 
Table II presents the data obtained 
at Akron in 1921 on the inheritance of 
spikelet disarticulation. (Since the 
plants of Burt oats at Manhattan did 
not attain full development because of 
the ravages of chinch bugs, accurate 
classification with regard to spikelet 
