Nov., 1903 .] 
The Development of Corn. 
3 
THE DEVELOPMENT OF THE SPIKELET AND 
GRAIN OF CORN.* 
C. C. Poindexter. 
With a view to a later study of the subject of xenia in corn, a 
preliminary observation of the development of the carpel and 
endosperm was attempted in order to see what relation exists 
between them, since some of the authorities mentioned claim that 
the effect of double fertilization is shown in the carpel wall, while 
others assert that it is shown only in the endosperm and embr3’0- 
sac. The embryology of the corn grain also was studied and 
figures were made of the ovule at different stages beginning with 
the archesporial cell and ending with the fully developed embryo. 
These drawings and observations not being complete will be 
reserved for another paper. As there are few recent descriptions 
and figures of the develor ment of the spikelet and grain, it was 
thought advisable to publish this general part at the pre.sent time. 
The writer wishes to acknowledge his indebtedness to Professor 
John H. Schaffner for invaluable suggestions and criticisms in the 
preparation of the paper. 
The material used was common white field corn gathered at 
different stages of maturity from the corn field of the Ohio State 
Universit}' in the summer of 1902. The ver>^ 3’oung ears were 
left whole or cut in two, while the larger were quartered length- 
wise and, after killing, cut into pieces convenient for use. The 
material was killed in chrom-acetic acid and preserved in 70 per 
cent alcohol and later imbedded in paraffin. Pieces of the 3'ounger 
ears were cut from three to six grains in length, while single 
grains were used of the older stages. The sections were cut 
12-18 fj. in tliickne.ss, and stained on the slide in anilin-safranin 
and gentian-violet and iron-alum-haematox3din. All things con- 
sidered, corn is an eas3" object to work with, but in using the older 
grains precaution should be taken to guard against shrinkage of 
the endosperm tissue. This ma3' be practicall3' obviated by punc- 
turing the grain with a dissecting needle before killing. The 
outer covering of the.se grains may also be sliced off on either side 
to permit of rapid penetration. The iron-alum-haematoxalyn 
proved to be the most efficient stain and was soon the only one 
used. 
The production and development of new varieties of plants 
depends upon the fact that the offspring of a cross par- 
takes of the characters of both parents, which, according to Men- 
del ( I ) follows a definite law of proportion in some species. 
Some plants appear to be more susceptible to hybridizing than 
"Contributions from the Botanical Laboratory of Ohio State University. XIV. 
