192 REporT OF THE BoOTANIST OF THE 
become yellow; but the unthrifty condition brought about by 
such causes should be carefully distinguished from the genuine 
yellows. The most reliable symptoms of yellows are premature 
ripening of the fruit and the occurrence of red streaks in the 
flesh of the fruit. 
Brown Spot (Helminthosporium carpophilum Léy.).—During the 
past two years we have frequently seen peach fruits affected 
with a fungous disease called brown spot. It begins its attack 
while the fruit is still green, but is most conspicuous on the ripe 
fruit where it apears in the form of pink spots and cinnamon- 
brown areas. At first the spots are no larger than a pinhead 
and have a brilliant pink color such as the San José scale insect 
produces on apples and pears. In the center of the pink spot 
there is usually a circular, brown or fawn-colored portion. At 
this stage the spots are often slightly elevated. In time, the 
spots coalesce to form irregular areas of cinnamon-brown color 
and then the pink discoloration of the fruit mostly disappears. 
Such areas may occupy from one-fifth to one-half of the surface 
of the fruit and, according to our observations, occur exclusively 
upon the upper surface. (See Plate XXV, Fig. 2.) 
Ordinarily no spores are found in the younger spots, but on 
the older, brown areas the spores of an Helminthosporium occur 
sparingly. The spores are light brown and mostly 2- to 3-septate 
although 4- to 6-septate spores are not uncommon. In almost 
any microscopic preparation containing scrapings from the 
brown areas there may be found a few of the Helminthosporiuin 
spores, but they are never abundant. There is little doubt that 
these spores belong to the fungus which causes the brown areas, 
and that the fungus is Helminthosporium carpophilum® Léy. 
What seems to be the same fungus” has been found on peach 
branches. Conspicuous enlargements resembling the black knot 
of plum frequently occur on peach branches in this State. (See 
*According to Aderhold (Centralblatt f. Bakt., Parasitenk. u. Infektionskr., 
II, 5:523.) Helminthosporium ecarpophilum Lévy. is a synonym of Clas- 
terosporium amygdalearum Sace. 
“The fungus grows readily on the ordinary culture media. The spores 
germinate freely in tap water and in distilled water; but in the latter med- 
