168 Field, Forest, and Wayside Flowers 
Just inside the innermost skin of the wheat- 
grain there is a layer of nitrogenous substance, far 
richer in nutriment than the starchy sub- 
stances which lie beneath it. When the 
integuments of the wheat-grain are torn 
off, this nutritive ‘‘aleurone’’ layer is apt 
to come away with them. But any proc- 
ess of milling which can keep the 
aleurone with the starchy inner part of 
the grain will produce a flour highly nu- 
Fic. 42.— tritive in proportion to its bulk. 
Caryop- . 
sisofthe The parts of the grasses are simple and 
wheat. 
(From the few, but Nature can so vary their forms 
Vegetable 
wees and their arrangement that botanists rec- 
ognize about four thousand species, of which over 
two hundred and sixty grow east of the Rockies. 
The number of flowers in each spikelet varies 
greatly in different species. Sometimes there are 
a dozen or more—sometimes there is but one, 
with rudiments and traces of others above it. 
The spikelets may be ranged down one side of 
a main axis in compact, straight rows; they 
may surround the axis, as they do in “timothy” 
grass, forming a cylinder of bloom, or they may 
dangle, as the oat-spikelets do, at the tips of 
slender branchlets, which form part of larger sprays. 
