102 : A GRAIN OF BARLEY. 
In the first place, we can prove beyond doubt that some of 
the minute granules are simply spherules of fa¢ or o7/. Then 
again, whilst others dissolve readily in water and behave like 
true vegetable albumin, others belong to the class of glodudins, 
” 
whilst a large portion of the ‘‘aleurone” consists of a form 
of albuminoid which is only soluble in dilute potash. 
Aleurone grains, which in the main consist of proteids 
belonging to the class of globulins, are found in many other 
seeds, but generally speaking, they occur in the same cell as 
the starch grains. This is the case, for instance, in the 
cotyledons of the bean, the pea, and the lupin, and in fact 
in the seeds of leguminous plants generally. In the Order 
of Grasses, however, the aleurone grains and the starch 
grains occur in distinct cells. What end is gained in the plant 
economy by this differentiation remains yet to be shown by 
future research. 
Whilst on the subject of these aleurone cells, I may perhaps 
be pardoned for making a small digression, which possibly may 
not be altogether uninteresting to some of you. 
When wheat is ground, the object of the miller is to remove, 
as far as possible, the outer integuments of the grain in the 
form of van, and to produce a very white flour from the 
inner starchy portions. The bran consists mainly of the 
pericarp and testa, but since the adhesion of the testa to 
the endosperm is very great, the layer of aleurone-cells is 
always removed with it. Now, as we have seen in the case 
of barley, the contents of the aleurone-cells consist of highly 
nitrogenous substances, and as such substances, generally speaking, 
are very nutritious, many people have condemned the use of the 
higher grades of flour, maintaining that the rejection of the 
whole of the bran is very wasteful, and that we ought to eat _ 
“whole meal” bread. I must say that the chemistry of the 
subject goes rather against these people, but quite recently 
very considerable light has been thrown upon the matter 
by a very remarkable series of experiments carried out upon 
