472 
Journal of Agricultural Research 
Vol. XXV, No. I* 
and the present paper, which embodies a correlated report of these results, 
has finally been compiled at the suggestion of the senior author. The 
aim has been to give an adequate account of the disease as observed 
independently at the three locations, together with the evidence as to 
its etiology and the characters of the pathogen. 
HISTORY AND DISTRIBUTION 
Observations throughout the period covered by these investigations 
show that the disease appears every year throughout the growing season 
but is not usually the cause of serious damage. It is not conspicuous 
in the field except in periods when moisture conditions are especially 
favorable for its development. Observations made in Wisconsin, both 
in the vicinity of Madison and elsewhere in the State, in various parts of 
Iowa and Indiana, and at a number of widely distant points in North 
Carolina, also in Virginia, Maryland, and the District of Columbia, 
indicate that this .disease is of very general occurrence. It doubtless 
occurs widely at least in the United States and has heretofore escaped 
notice because of its confusion with other clover leafspot diseases. 
Mention has been made in previously published accounts of several 
bacterial diseases of clover. The first of these was described in 1896 by 
Voglino (7). 3 This account deals with a leafspot disease which was 
rampant in several provinces of Italy on white clover, was common on 
Trifolium resupinatum , but rarely attacked red clover. It caused the 
formation of definite, usually numerous small black spots, most evident 
on the lower leaf surface. The floral parts were also involved and 
presented a similar diseased appearance. Voglino concluded that this 
disease not only materially reduced the yield of forage but also rendered 
it distasteful to grazing animals. The disease was ascribed by him to a 
bacterial parasite which he described as a new species, Bacillus trifolii. 
So far as can be determined, this disease has thus far not been reported 
outside of northern Italy. 
Although this Italian disease and the bacteriosis under discussion 
have certain characters in common, they differ in several important 
features. In the first place, the cultural characters, then not regarded 
as of special significance but now considered essential to the exact 
description of species of bacteria, are almost wholly lacking in Voglino's 
description. Further, Bacillus trifolii is described as 0.5 to 5.0/x in length 
by 0.2 to 0.5/x in width and is thus more slender than the organism 
associated with the disease under discussion. In addition, it forms, as 
shown in Voglino's figures 10 and 11, drumstick-like spores, a character 
not possessed by the organism herein described. Then, too, even in the 
absence of type specimens with which to make direct comparison, his 
figure 1, which illustrated the character of the lesions on the foliage, 
leaves no doubt that Voglino’s disease is distinct from the one dealt with 
in the present paper. 
A disease reported from Italy in 1913 by Baccarini and his associates 
(r) under the name “ incappucciamento ” manifests itself in a very 
different manner from the leafspot disease described by Voglino. Since 
this malady was so severe in northern Italy as to cause a failure of the 
crop, a commission was assigned to investigate it. Doctor Bargagli, 
bacteriologist for this commission, believed it to be of bacterial origin. 
This clover disease is characterized by a general stunting of the above¬ 
ground portions of the plant, as indicated by the dwarfed, yellowish 
1 Reference is made by number (italic) to literature cited, p. 490. 
