A Bacterial Disease of Alfalfa 5 
droplets. This exudate dries in a short time with a glistening 
finish, and gives the stem very much the appearance of having been 
varnished, and where the liquid has collected in little amber colored 
scales and has hardened, it looks as if the varnish had run and 
dried. Stems in this condition have a dry, slightly rough feel to 
the touch. The exudate also dries uniformly over the surface or 
just beneath it, and there produces a dark brown, resinous surface 
which blackens with age. Such stems are very brittle and easily 
broken, which fact makes it almost impossible to handle the crop 
without an immense amount of shattering. 
If the epidermis is scraped from an infected stem, the tissue 
underneath has the same yellowish, watery appearance. This path¬ 
ological condition extends to the center of the stem and if it is split 
lengthwise, the interior cavity presents a brownish, mealy aspect. 
Such stems will collapse much more readily when pressed between 
the fingers than healthy ones. A shoot in this condition is virtually 
girdled; its circulation is impaired and its food supply is practi¬ 
cally cut off as is evident from the poor growth it makes. Some 
stems remain in this inactive state and struggle along until the 
mowing machine puts an end to their existence; others turn black, 
shrivel and die six weeks before time for the first cutting. During 
the past season, the disease appeared about May 15th, and up until 
June 10, twenty-six days later, there were no blackened stems to 
be found. During this period, the trouble was manifested by the 
characteristic yellowish green, watery look. 
The leaves attached to the diseased part of the stem usually 
show a watery, pale yellow color at the base, along the mid rib of 
the leaflets, and especially in the tiny petioles. Those on the parts 
of the stem which are blackened are always dried up, yellow and 
extremely brittle. The stipules at the base of the petioles are yel¬ 
low and brittle and usually show the disease before their correspond¬ 
ing leaves. 
Sometimes the leaves exhibit the infection independently of 
the stem. In this case the petioles become watery, pale yellow and 
droop. The malady may be confined to the petiole and base of the 
leaflet or it may involve the whole of the blade. Occasionally leaves 
are found where the inoculation has been made, apparently, in the 
margin of the leaflet, and the infection has proceeded toward the 
middle. In such instances, the tender tissue has a watery look, as 
if it had been bruised. These leaf infections have been observed 
to occur a little earlier than the stem troubles, although it may be 
merely a matter of being able to detect the pathological condition 
there first. 
One year old plants may exhibit blackened areas in the crown, 
and black streaks which run down into the tap root. As the plant 
