DISTINCTIONS IN CULTIVATED BARLEYS. 31 
tion to generation. In other cases the color appears intermittently 
or sporadically in strains and tissues ordinarily free from pigments. 
This erratic behavior, coupled with the fact that white, brown, 
black, violet, purple, amber, and blue-gray have been used in various 
classifications, led the writer to make a study of the pigmentation of 
barley. Since the colors in the seed seemed to be more numerous and 
less variable than in the other parts of the plant, the grain was used 
as the basis for the investigation. 
The technic was adapted from that used by Mann (18) in his 
identification and location of the pigments in the cowpea. The 
grains were first examined by sectioning them dry. This avoided 
any modification such as might easily come from the action of solv- 
ents in an embedding process, or even from water if a freezing 
method were used. The hand sections were equally as satisfactory 
as those made with a microtome, as the areas in question were readily 
defined and the colors more easily seen in moderately thick sections 
than in very thin ones. The reagents most extensively employed 
were caustic potash, hydrochloric acid, and chloral hydrate. The 
sections were placed dry upon a microscope slide underneath a seven- 
eighths-inch cover glass, held in place by a drop of paraffin on either 
side. The reagents were drawn beneath the cover glass by means of 
blotting paper and their action watched through the microscope. 
Two per cent solutions of the acid and of the alkali and a saturated 
aqueous solution of chloral hydrate were used in these tests. If the 
pigment showed no change within a few minutes, the reagents were 
allowed to remain upon the section for some hours. In such cases, 
larger pieces were also placed in small vials containing 15 per cent 
solutions and examined at the end of 24 hours. 
It soon became apparent that there were two pigments in barley. 
One was readily affected by the weak solutions, and from the nature 
of its reaction was undoubtedly anthocyanin, which occurs widely in 
the plant kingdom in both its red, or acid, and its blue, or alkaline, 
form. The other resisted even prolonged soaking in the more con- 
centrated solutions and was probably a melaninlike substance. 
The first varieties studied were those in which the adhering glumes 
were black. No change was effected by either the weak reagents or 
the prolonged soaking in concentrated solutions. The black did 
indeed become a brown, but this was most probably due to the dis- 
tention of the pigment-containing tissues attendant upon the absorp- 
tion of water. As a considerable number of varieties with black 
glumes were tested and as the results were uniformly the same, it 
would seem that a black or brown pigment in the glumes may be 
attributed to a melaninlike compound. 
A number of Abyssinian varieties with purple glumes were sec- 
tioned and treated with the reagents. The purple color responded 
