



* Report of the Botanist 

The work during 1885 has been mainly in the line of that detailed 
in the report for last year, that is, the study of plant diseases. The 
observations which it seems desirable to speak of in this connection 
are partly in continuation of those already reported, and partly on 
other diseases. A study was also made of a new parasitic disease, of 
a@ noxious insect recently introduced into this country, the clover- 
leaf weevil; and some notes are given on weeds and their fungous 
parasites. These topics will be taken up in the following order: 
Pear blight, 
Spotting of quince fruit, 
Rotting of tomatoes, 
Rust and mildew of lettuce, 
Rotting of cherries and plums, 
Disease of clover-leaf weevil, 
Weeds and their fungous parasites. 
PEAR BLIGHT. 
Micrococcus amylovorus B. 
The investigation of this disease has been in continuation ot last 
year’s work, and has been prosecuted throughout the year. Many of 
the results obtained have been already given to the public in one 
form or another +, and to some extent, therefore, the data given in 
this connection is not entirely new. 
The most prominent results of the season’s work are the confirma- 
tion of the theory that the blight is due to bacteria, and the discov- 
ery of the manner in which the germs enter the tree; these topics 
will be taken up first. 
It was stated at the outset in last year’s reportt that the bacterial 
theory of pear blight, although exceedingly plausible, was yet not 
fully demonstrated. Both a positive and negative proof were con- 
sequently undertaken in order to secure a solid basis for our argu- 
ments. ‘The work of last year showed beyond all question that the 
disease is readily communicated to suitable, healthy branches, by 
introducing a drop of watery solution of a diseased part, or of the 
PoC. Arthur. 
{Bulletin II. of this Station, new series; ‘Proof that the disease of trees 
known as pearblight is directly due to bacteria,” read before the Amer. Assoc. 
for the Advancement of Science, August 1885, and published in Botanical 
Gazette, X, p. 343, and in Gardener’s Chronicle, XXIV, p. 586; ‘ Pear blight 
and its cause,” American Naturalist, XIX, p. 1177; an oral address to the Am- 
erican Pomological Society, August 1885, and to the N. J. State Horticultural 
Society, December 1885, not yet published by the societies, but variously re- 
ported in many journals; and other less important communications. 
¢Third Annual report, p. 357 and 364. 
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