HOWARD AND HOWARD. 21 
Neergard' in expressing the density of the ear by a number (D) 
which gives the number of spikelets per 100 mm: of the rachis. 
Most of the common wheats are very much alike as regards den- 
sity. From the measurements of D in the Punjab 1908 crop they 
fallinto two groups represented by densities of 20 or 24. This fact 
combined with the great variation in density produced by the con- 
ditions of growth in India has led us to reject density as a means 
of distinguishing the kinds in India. Differences in soil moisture 
and nutrition affect the length of the ear considerably, while 
the onset of the hot weather often cuts short the development of 
the later shoots, the ears of which are much shorter and denser than 
the earlier formed ears on the same plants. We have found that 
greater differences in density in ears of the same plant can be obtained 
than exist between different kinds of common wheat. Eriksson? 
has laid great stress on density in his classification of Kuropean 
wheats and in fact divides up his botanical varieties by means 
of this character. The conditions in India are such that his classi- 
fication could not be usefully adopted. 
(c) Character of the spikelets and glumes.—In one instance the 
shape of the spikelets and glumes has been used to help to separate 
two kinds very similar in most other respects. The ease with which 
the spikelets shed their grain is also an important character and one 
which is very constant for any particular kind. As a general rule 
in India, the beardless wheats shed their grain more readily than the 
bearded forms and are consequently not favourites with the ryots. 
Thin glumes generally go with easily shed grain while the thick 
glumed forms hold their grain much more strongly. An extreme 
case of a thick glumed wheat which holds the grain is to be seen in 
Indian Emmer. 
The character of the keel of the outer glumes is of great import- 
ance. In macaroni wheats the keel is very pronounced right down 
to the base of the outer glumes, while in the dwarf and common 
! von Neergard, Normal system fir bedémande af axets morfologiska sammansittning hos 
vara sddesslag, Alim. svenska Utsddesfireningens anberittelse fir ar 1887, s. 37. 
2 Eriksson, 1. c, See also Fruwirth, Bd. LV. page 146. 
