24 
BULLETIN 1386, U. S. DEPARTMENT OF AGRICULTURE 
toward a definite, configuration in the caryopsis which results from 
the bending of its axis can be discerned, and the average form can be 
taken as being the one typical of the variety. 
Some minor differences in the conformation, as delineated by the 
periphery and by the longitudinal lines, are of sufficient importance 
to be noted. These differences pertain to the relation of the thick- 
ness of the caryopsis to its width, to the relative thickness below 
and above the middle, to its form at the summit and at the base, 
and to secondary features of form. They are usually best seen from 
a lateral viewpoint. As they are sometimes difficult to describe 
accurately they can usually best be represented by means of sketches 
or drawings. Some of them are shown in Figure 1 and in Plates 
X1Y. XV, and XVI. A. Some of these less conspicuous and less im- 
portant characters are as follows: (1) The scutellum varies in 
length as compared with that of the entire caryopsis and as to con- 
formation and prominence. Some of these differences have been 
found to be constant; for example, in one or more varieties most 
Fig. 1- — Caryopses of four varieties <■!' sorgo: l, Minnesota Amber (Sugar riant No. 
0231115) ; /.'. Folger (Sugar Planl No. 021570); <\ Orange (Sugar Planl No. 01959); 
I), Red X (Sugar l'lnni No. 021693 96). The differences in conformation are in part 
(In.- to differences in curving 
of the caryopses show the scutellum prominent; in certain of them 
it is usually straight and in other- it is usually curved. (2) The 
caryopsis is also sometimes tumescent on the ventral side. (3) The 
radicle i^ always prominent in one or more forms. In others it is 
never conspicuously so; and when this character is used for identi- 
fication it is necessary to discriminate between varieties in which 
it only occasionally or slightly projects and those in which 
it is outstandingly prominent. (4) The pericarp is transversely 
wrinkled on the ventral side in some varieties. (5) The style bases,, 
in addition to showing differences in direction assumed, are occa- 
sionally thickened, and in one or more forms they are seen to origi- 
nate in a fold of the pericarp. In general, such minor differences 
are less dependable on account of fluctuation than characters of the 
glumes. The plumule, for example, is sometimes somewhat promi- 
nent, but is not outstandingly and constantly so. So, too, in certain 
varieties the radicle and the scutellum are somewhat prominent 
but can not be said to be conspicuously and constantly so. 
