tg0% | SMITH—A BACTERIAL DISEASE OF OLEANDER 309 
has still further restricted the limits of best growth to between 35- 
37-8° C. Several experiments were conducted by the writer with 
the oleander organism in temperature about 35.5° C, and no growth 
took place on agar, bouillon, or potato after four days, although 
there was good growth in the inoculated bouillon tube at room 
temperature. 
All the liquid media become at first acid to litmus, but change 
to an alkaline reaction in about two weeks. The media used were 
all titrated to +1.5 to phenolphthalein. This would be slightly 
alkaline to litmus, so the growth of the organism caused first an 
acid, then an alkaline reaction. All the cultural characteristics of 
the oleander organism, so far as possible, were compared with those 
described from the olive organism. There seems to be a very close 
agreement, and without question the organism is identical. 
From knots produced by artificial inoculations on olive and 
oleander the organism was isolated (in the same manner as described 
before) and grown in the same media as was the original culture 
from the oleander. These two series agreed perfectly in culture 
characteristics with one another and with the original culture. 
The organism also was isolated from naturally infected olive 
knots in the same manner as for the oleander. Growth on various 
culture media showed biochemical and cultural characteristics that 
agreed with those observed by the writer for the oleander knot; and 
with those described by Savasrano in his study of the olive knot. 
This oleander disease is not believed to be a new trouble, but 
Similar to the one found on olives. They are both caused by a 
motile rod (Bacillus) that grows well on the ordinary culture media, 
and will cause infection of the olive and the oleander. This infec- 
tion at length causes characteristic lesions and knot-like growths on 
_ the stem and leaves, The knots produced on the olive by the oleander 
organism agree with typical knots as found on cultivated olives in 
California, and with various illustrations of the olive knot. » The 
cultural characteristics of the two are similar in all essential respects. 
LaBoraToRY OF PLANT PATHOLOGY, 
University of California, Berkeley. 
