4 BULLETIN 611, U. S. DEPARTMENT OF AGEICULTTJKE. 
planting extensively I should expect that disease to be serious. That would be 
my forecast of the matter. The humidity and cloudy weather in the East 
ought to be more favorable to the disease than the climate of California. 
There is no reason to suppose that blight will not appear wherever 
Persian walnuts are grown. 
THE DISEASE IN THE EASTERN STATES. 
During the first week in June, 1916, a trip was made by the writer 
to various points in Delaware, New Jersey, and Pennsylvania where 
bearing walnut trees were known to be located. On practically every 
tree that had a crop the nuts were found to be spotted in a manner 
very characteristic of bacteriosis (PL I). The lesions at this time 
were small and superficial in character, rarely extending more than 
2 to 3 millimeters (about one-tenth of an inch) into the husk. A 
number of specimens were collected and cultures obtained. 
The technique used consisted in washing the nuts with soap and 
water, sterilizing the surface with an alcoholic solution of mercury 
bichlorid for five minutes, and then washing in distilled water. 
After this treatment the epidermis of the diseased spots was removed 
carefully with a sterile scalpel and bits of subepidermal tissue trans- 
ferred to tubes of melted beef agar, agitated, further diluted in a 
second and third tube of the same media, and poured into Petri 
dishes. About 15 attempts were made, in practically all of which 
bacterial colonies of a similar type appeared on the plates in from 
two to four days, and the plates from the third dilutions usually 
contained colonies which were so few as to allow transfers to be 
made to tubes without difficulty. During the first w T eek in August 
a series of inoculations was made on the nuts and twigs of a certain 
mature tree at Lancaster, Pa., which was said to be a seedling of 
Rush. The husks of 24 young nuts entirely free from any trace of 
the disease were inoculated (1) by spraying with a suspension of 
the germs in rain water, (2) by smearing on the culture, and (3) 
by puncturing with an infected needle. Several untreated nuts w r ere 
tagged as controls. At the same time five young, tender, growing 
twigs 5 to 10 millimeters in diameter were inoculated w 7 ith the germs 
about 6 inches from the tips by making several punctures in each 
with an infected needle ; one twig was punctured with a sterile needle 
as a control. The organisms used in these experiments w r ere all from 
pure cultures on beef agar and obtained as previously described. 
A month later (Sept. 5, 1916) it was found that 21 of the 24 nuts 
inoculated had developed the disease and 3 showed no trace of it; 
the untreated nuts w T ere perfectly clean. Of the five twigs inocu- 
lated, all had developed cankers from 5 to 10 mm. in length and from 
2 to 5 mm. in width. Plate II shows one of the nuts 30 days after 
