Some Tomato Diseases. F. T. Brooks and G. O. Searle. 183 
Form L. Aerial mycelium, white, scanty, evanescent, ad- 
pressed to the medium. Pycnidia exceedingly numerous, brown, 
with light brown spore masses, generally half-submerged in the 
medium, some wholly submerged. This was a very constant 
form on all media, always showing very scanty mycelium and 
exceedingly numerous brown pycnidia. 
Form M. Aerial mycelium plentiful, tending to be matted, 
greyish white. Pycnidia fairly numerous, scattered at the top of 
the culture and aggregated towards the bottom, brown to light 
brown in colour, with yellow brown spore masses. On other 
media the production of pycnidia was slight except on sterilised 
tomato stems, where they were very numerous and black in 
colour. 
Form N. Aerial mycelium very scanty, evanescent, white. 
Large, confluent, salmon pink spore masses. Mycelium was 
always rather scanty except on potato cores and _ sterilised 
tomato stems, but the cultures were very distinct by reason 
of the large confluent masses of Fusariwm spores. 
Form P. Aerial mycelium very profuse, white, matted. 
Pycnidia very few, scattered, brown, large. On different media 
the pycnidia varied from brown to black. 
Form Q. Aerial mycelium fairly plentiful, white, closely ad- 
pressed to the medium. Pycnidia very few, brown. Spore 
formation very sparse on all media. 
Form S. Aerial mycelium very scanty and almost entirely 
evanescent. Acervuli very numerous, black, scattered all over 
the culture. In earlier stages the medium took on a pinkish tinge. 
Form T. Aerial mycelium very scanty and evanescent, 
white. Pycnidia numerous, yellowish brown, later a red brown, 
entirely covered with profuse, pink spore masses. The colour 
of the pycnidia and spore masses varied considerably on various 
media; pycnidia dark brown on potato agar, light brown on 
tomato agar; spore masses dirty pink to salmon colour on 
tomato agar, brick red on potato cores. 
Form U. Aerial mycelium profuse, grey, adpressed to the 
medium. No fructifications were produced by this form on any 
medium, which was disappointing as it was the only culture of 
an authentic Mycosphaeralla citrullina and so was important 
for comparative purposes. 
Before discussing the microscopic characters of the various 
forms and comparing them with the herbarium and other 
material obtained, it will be convenient to divide them into 
groups. 
The first and most important section, Group A, contains all 
the forms having a pycnidial type of fructification and probably 
belonging either to the genus Phoma or to the genus Diflodina. 
I2—2 
