i5 
A Disease of Tomatoes. 
tomato plants, and upon sending to Mr. Massee a specimen of the 
fungus on the fruit, he pronounced it to be “ Ascochyta citrullina, 
C. O. Smith, the conidial form of Mycosphcerella citrullina, 
Grossenbacher.” 
The young pycnidia on the tomato were pale brown in colour, 
and became darker with age, the spores were hyaline and occasionally 
uniseptate. The measurements both of the pycnidia and spores 
were about the same as those given by Massee in his description 
of Ascochyta citrullina. When mounted in water and observed 
under the microscope, mature pycnidia were seen to liberate their 
spores in a coil-like manner through the ostiole. The pycnidia 
obtained from the stems of tomato plants liberated their spores 
in the same manner. 
As material of the fungus was available both from fruit and 
from stem it was thought desirable to grow the fungus from the two 
sources on artificial media and to perform inoculation experiments. 
The fungus obtained from the fruit was placed in the stems, and 
the fungus from the stem was placed in the fruits. In this manner 
it was hoped to establish more completely the identity of the 
fungus from the two sources. 
Cultures of the Fungus Isolated from the Fruit. 
On account of the method of liberation of the spores it was 
easy to obtain them in a fairly clean state and establish pure 
cultures of the fungus. The spores germinated readily both in 
water and in a dilute solution of sugar. 
On tomato extract containing 10 per cent, of gelatine the 
fungus grew well, forming a dense white mycelium which began to 
sink into the medium after 8-10 days, at the same time causing 
liquefaction of the gelatine. The mycelium did not produce spores 
when grown on this medium. 
On tomato-agar, i.e., agar containing tomato extract, the 
mycelium grew less vigorously but pycnidia developed in considerable 
numbers. These fructifications were brownish in colour and 
similar in structure to those obtained on tomato fruits, but were 
more variable in size. The spores were similar to those produced 
by pycnidia that developed in the tissues of the plants. In old 
cultures the spores exuded from the pycnidia and formed blobs of a 
pinkish colour at their orifices, though the masses of spores 
sometimes spread over the surface of the pycnidia or the medium 
in the immediate vicinity. In these cultures there was often a 
tendency for the pycnidia to be distributed in concentric circles 
