241 
details, of ^interest only to those who are pursuing similar studies, are 
given in small type at the close of the article. 
\ 
tear leaf-blight ( Untomosporium maculatum Lev.). 
This disease is perhaps the greatest obstacle to the profitable iiro- 
duetion of pear stocks. The principal injury is caused by a premature 
defoliation of the seedlings. When such defoliation takes place early 
in the season, as is quite commonly the case, the young seedlings are 
forced to form a new set of leaves, presumably at great expense to the 
reserve material stored for use the coming spring. Often this forma¬ 
tion of new leaves is repeated two or three times, the seedling finally 
becoming too exhausted to continue the struggle. If the following 
winter be survived, enough growth may be made to render budding 
possible. 
Although the disease is very abundant on bearing trees further south r 
it seems to be confined in western New York, at least in its severe 
attacks, to one, two, and three year old seedlings, occasionally defoli¬ 
ating a budded stock of some susceptible variety like the Flemish 
Beauty. All ordinary budded stocks are commonly immune from the 
disease, although the stocks into which the buds are inserted may 
have been diseased before being budded.* So far as the author’s observa¬ 
tions go the fungus causing the disease does not attack the seeds of 
the pear or the cotyledons of the young seedlings until two weeks after 
the appearance of the latter above the surface of the soil. Early in the 
season it attacks only the foliage, but later, as the defoliation continues,, 
it is found on the succulent growing tip of the stem. For 3 or 4 inches 
from the terminal bud the bark is covered with small, sunken spots,, 
bearing in their centers the mature fruiting bodies of the fungus, this 
condition first becoming noticeable about the middle of August. ' As 
first pointed out by Sorauer,f it is in these sunken spots that the 
parasite passes the winter. In America the parasite lives from 
year to year, as it does in Germany, upon the bark of the grow¬ 
ing seedling and infects the young leaves upon their first appearance 
in the spring. On May 20, before the foliage of last season’s un¬ 
budded stocks was two-tliirds grown, mature pustules were found 
upon the young leaves in immediate proximity to these spots upon the 
twigs. A microscopic examination of the spots revealed the parasite 
in an active condition. There is little doubt that the infected twigs 
*The terms “seedlings” and “stocks” are here employed as in common nse among 
nurserymen. A seedling in nursery parlance means a plant grown from seed before 
it is transplanted into the nursery row, while the term stock is used to designate the 
seedling after transplanting either before or after budding. Whenever I have referred 
to stocks which have been budded I have used the terms “budded stocks” or “ buds.” 
i Sorauer., P. Handb. d. Pflanzenkranklieiten. Zweitc Anil., 1886, vol. ir, p. 373. 
Monatschr. d. Ver. zur Beford. d. Gartenb. Kgl. preuss. St., Jan. 1878. (Cited by 
Frank, Ivrankh. d. Pfl., 1880, p. 590.) 
