

dL 
apple trees. Proc. Amer. Assoc. Adv. Sci., vol. xxrx, 
1880, p. 583. [14 pages. | 
Same matter essentially in Amer. Nat., vol. xv, 1881, 
p. 527. [5 pages. ] | ; 
Same matter with additions in Trans. Ill. Hort. Soc. 
for 1880, p. 157. [11 pages. ] 
Abstract in Fruit Recorder, vol. xm, 1880, p. 134. [1 
col. | 
Abstract in Amer. Jour. of Micr., vol. v, 1880, p. 219. 
[24 col. | 
Abstract in Science, vol. 1, 1880, p. 162. [1 col.] 
Brief abstract in De Bary’s Volesungeniiber Bacterien, 
1885, p. 1387. [4 page. | 
The fire blight of the pear and twig blight of the apple are declared to be 
the same, and the disease also affects the quince, butternut, Lombardy pop- 
lar, American aspen, and possibly the peach. 
The destructiveness and extent of the disease are noted, and a brief ac- 
count of the literature of the subject given. 
Experiments in inoculation were begun July 1, 1880, using Clapp’s Favorite 
and Bartlett pears. The first trals were made by inserting pieces of dis- 
eased bark as in budding, but afterward the viscid exudation was thinned 
with a little distilled water and applied by nipping a needle or pointed 
knife in it and puncturing the bark, mostly in shoots of the current year’s 
growth near their middle longitudinally, or at the apex. Ten experiments 
on thrifty apple trees in the last year’s growth all failed. Twenty-one trials 
in which the virus was applied to the uninjured surface of twigs and leaves 
all failed. ‘‘Of inoculated pear trees sixty-three per cent. became diseased, 
exhibiting all the characteristics, externally and internally, of fire-blight.” 
Of the four quince trees all became diseased, and of the thirty-six pear 
trees, thirty per cent. became diseased. The virus of all was taken from 
the pear. 
Large limbs with the disease in active progress were bound among healthy 
branches July 1, with favorable meteorological conditions, without result. 
The popular opinion that the disease is a rapid one is shown to be erroneous, 
it really being very slow. The bark of a limb may be affected through full 
four feet with the limbs still remaining green. Infection rarely shows in 
less than nine days, and then progresses no more than an inch per day. 
The disease has been observed making progress during two winters ; in 
one instance it continued into the spring, in the other it suddenly stopped 
at the time the leaf buds expanded. 
The size and appearance of the bacteria are described. The chief change 
observable in the tissues of the plant is the early removal of the stored 
starch; the walls of the cells do not appéar to be affected. In young parts 
all éhe tissues except the epidermis seem equally affected, but in older limbs 
the chlorophyll-bearing cells of the bark are the first and chief seat of the 
disease. ‘The cambium is tardily affected. 
The chemical products of this disease, determined by Prof. H. A. Weber, 
are said to be carbon dioxide and butyric acid. 
1881. PrFFER, GEo. P. (Pewaukee, Wis.), and others. 
Apple tree blossoms—blight [with discussion]. Trans. 
Wis. Hort. Soc. for 1881-2, vol. xi, p. 194. [81 pages 
on blight. | 
In making a special study of apple blossoms in the spring of 1881 the fol- 
lowing facts regarding blight were observed : The first flowers appeared 
