BRIEFER ARTICLES. 
WALNUT BACTERIOSIS. 
I CHARACTERIZE here briefly a new micro-organism pathogenic to 
Juglans regia and related species, which has been under investiga- 
tion at this laboratory for several years. Announcements of the isola- 
tion of the organism and a demonstration of its pathogenic action on — 
walnuts were contributed several years since to the leading horticultural 
journals of the Pacific coast. Further communications relative to this 
disease are in course of preparation, which will enter more fully into 
the characterization of the organism, its pathogenic powers, its cultural 
peculiarities, and will give full details as to the nature and treatment of 
the disease which it causes. 
Pseudomonas juglandis, n. sp.—A short, rod-shaped micro-organism 
with rounded ends, actively motile, bearing a single long polar usually 
wavy flagellum. Length of organism, taken from colony in acid gela- 
tin, set directly from walnut, and stained with gentian violet, 1-24, 
according to whether the germ has just divided or has elongated but 
not yet divided. Just before separation a pair of germs will usually 
average about 2m in length. Average breadth of organism about 
0.5m. Occurs singly or in pairs, and sometimes in shorter or longer 
chains. Produces a bright chrome yellow growth on potato and many 
other media. When growing normally on potato the starch is so acted 
upon by a diastatic ferment produced by the organism, that it is altered 
throughout a wide band beyond the margin of the culture of organ- 
isms. This band of converted starch may extend o.5-1™ or more 
beyond the margin of the growth or germs, appears white to the eye, 
fails to show normal starch reaction to iodine, yields marked grape 
sugar reactions, has an exceedingly sharp and well defined limiting 
outline, often passing so sharply through a cell as to include only the 
starch grains on one side of the cell. This broad and distinct ferment 
band distinguishes this organism at once from Pseudomonas Stewartt 
and P. hyacinthi, as well as from the more nearly related P. campestris, 
‘which occasionally forms a weak but much narrower band, and from 
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