580 Report oF THE HortTIcuLTURIST OF THE 
Report of the Secretary of Agriculture of the United States for 
1886, pp. 117 to 120. By the courtesy of the Secretary of Agri- 
culture we are enabled to present in this bulletin Figs. 1, 2 and 
5 of plate V in that report.* See Figs. 1, 2 and 5, plate 16. 
Dr. Halsted also treats of this disease in Special Bulletin Q of 
New Jersey Experiment Station, April, 1892. After giving an 
account of an experiment in spraying for the prevention of this 
disease, he says: “This experiment demonstrates beyond question 
that the celery blight can be checked by spraying with ammoniacal 
carbonate of copper, even after the fungus has become well estab- 
lished upon the plants, and may make all the difference between 
a fair crop and one that is too poor to harvest for the market: . 
One of the suggestions that this experiment offers is the import- 
ance of beginning the treatment early.” 
CrLERY PHYLLOSTIOTA. 
In Bulletin Q above quoted, Dr. Halsted treats of another leaf 
spot caused by a fungus known to science as /’hyllosticta Apu, 
Hals. He says: “After becoming familiar with it there is no 
trouble in distinguishing it from Cercospora, even when the two 
diseases are found on the same leaf. The Phyllosticta spot begins 
as a dull brown patch, never becoming of the light ashy color, SO 
characteristic of the Cercospora in one of its stages. This is a 
rapidly growing fungus, is particularly fond of moisture and 
flourishes in the shade, usually being found upon the younger or 
lower leaves. It was particularly easy to grow the Phyllosticta 
upon sterilized petioles in test tubes. The pycnidia (in which the 
spores are produced) would form and mature in great abundance 
within five days. While experiments have not been made upon 

*EXPLANATION OF PLATE 16. Fig. 1 illustrates a diseased leaf. Fig. 2 gives 
a magnified view of a section of a leaf through a diseased spot; along the 
upper and lower edges are seen the oulines of the empty cells which form the 
skin of the leaf. The interior cells are filled with the living substance of the 
leaf. The threads of the fungus are seen traversing the interior tissue and 
sending branches through the lower surface of the leaf to produce spores for 
a 

the propagation of the fungus. Fig. 5, still more magnified, shows the ger- C 
mination of the spores. In bulletin 49 of Cornell Experiment Station, page 316, - . 
Atkinson shows that the conidia are obclavate and not clavate as originally 
figured in the Department of Agriculture Report referred to. In Fig. 2 as | y 
shown here, the spores are therefore obclavate. 
BP's 
& - 
oe 
(ie wy 
4 
Lay 
Pry 
a2 
- 
id 
bh 
m 
t 
