4 BULLETIN 137, U. S. DEPARTMENT OF AGRICULTURE. 
along the same line and because, in many instances, this investiga- 
tion has merely attempted to discover whether results obtained by 
them were sustained under the great variations of the American cli- 
mate. In barley the greatest achievement at Svalof was the dis- 
covery of two kernel characters, which, by various combinations, 
gave four separations under each previous group. 
These investigators found that the rachilla in some barleys was 
covered with long straight hairs and in others with short curly ones ; 
also that the inner pair of dorsal nerves sometimes bore teeth and 
were sometimes smooth. The stability of these characters was ques- 
tioned by Broili (10), who claimed to have frequently observed one 
form in the progeny of another, Tschermak (13), Blaringhem (7), 
and others have supported the investigators of the Plant-Breeding 
Association at Svalof, at least so far as the basal bristle is concerned. 
Although none are to be compared with this discovery in importance, 
many other studies have been made at Svalof. At one time they had 
developed a very elaborate system of measurements made by means 
of many ingenious mechanical devices. They have, unfortunately, 
made no specific, comprehensive publication of their negative re- 
sults, but according to Xewman (20) and others they have aban- 
doned the use of many of the measurements that were formerly 
made. Of those retained, the most important from the standpoint 
of this paper is that of density. In the early history of the asso- 
ciation two or three varieties were obtained by the "elite" method. 
They chose an arbitrary density and made mass selections of spikes 
conforming to that measurement. Later, they used density as a 
means of valuing head measurements, as a long head if loose might 
contain no more grains than a short one if compact. They finally 
employed it in varietal description. Blaringhem (7), who has fol- 
lowed the work of the Svalof association quite closely, used density 
as an indication of purity and to reveal the effect of climate. 
The morphological characters of the seed coat and the kernel have 
been treated by Kudelka (16) and Johannsen (14), but there is no 
suggestion of usable varietal differences. 
The composition of the grain has been studied by a few American 
and a large number of European scientists. Le Clerc and Wahl 
(17), who have made the most comprehensive of the American 
studies, have clearly demonstrated that composition is of slight use 
as a varietal character for, while there are differences, the effect of 
location and season is many times greater than that of variety. 
Color in barley has been employed by all systematists, but has 
received very little analytical attention. Brown (11) has a note on 
the color in the variety coerulescens, and numerous authors have dis- 
cussed the occurrence of pigments in other plants. A recent article 
by TVTieldale (26) treats of the chemical nature of anthocyanin and 
traces its origin from a glucosid. 
