8 BULLETIX 842, TJ. S. DEPARTMENT OF AGRICULTURE. 
length, remain green longer and therefore mature somewhat later 
than the normal ones, and the glumes protrude decidedly outward 
end give a somewhat thickened appearance to the shortened spike. 
Depending upon the severity of attack, some or practically all flower- 
ing glumes on infected heads contain, in the place of normal kernels, 
hard, light-brown to dark-colored galls which are filled with nema- 
todes. These galls, though usually slightly furrowed on one side, 
somewhat as are wheat kernels, are shorter and not uncommonly 
thicker. This thickness of the galls often results in the spreading 
cf the inclosing glumes so as to expose the galls to almost full view. 
As a consequence of this, wheat heads thus infected may be readily 
detected in the field. "When young, the galls are light to dark green 
in color. They gradually become dark brown later, as the normal 
wheat heads ripen. Because of a general similarity, they were in 
France first confused with and mistaken for " smutted " wheat and 
called " ble nielle," but only a simple test is necessary to distinguish 
the two. A smutted grain is easily crushed by a little pressure and 
becomes a mass of smutty powder, the black spores, whereas the 
galls are hard and firm and break with difficulty. In Germany the 
galls were first associated with the seed of cockle (Agrostemma 
githago), a weed found commonly growing in wheat. This resulted 
in the disease being designated there as " Kadekrankheit." Only a 
cursory examination, however, is necessary to distinguish the smooth 
nematode galls from the black cockle seeds, which are covered with 
rows of short spines. In England the trouble is perhaps most 
commonly called " purples," on account of the color of the galls. 
Farmers and millmen in sections of this country where the disease 
occurs call wheat containing these galls various names, such as 
smutted, bunted, cockle, bin-burnt, and immature wheat. There 
have been instances, some of them recorded, where pathological in- 
vestigators in this as well as other countries, without making micro- 
scopic examinations, wrongly identified the galls as stinking smut of 
wheat (Tilletia tritici or T. levis). Some of the differences in size, 
shape, color, and general appearance between the nematode galls 
and the material for which they have been mistaken are shown in 
Plate IV. 
DIFFERENCES BETWEEN THIS DISEASE AND TULIP-ROOT. 
It seems desirable to point out differences between the malady 
discussed in this paper and the so-called stem disease, or ••tulip- 
root," of wheat and other cereals, which, while occurring in 
European countries, has not been reported on wheat in America. 
The two troubles have been confused both popularly and scien- 
tifically, doubtless owing to their occurrence together at times and 
