MYCOSIS 561 
second, an infiltrative type of lesion best seen in the lung. 
Under what seems to be a true picture of mycotic pneu- 
monia, dirty gray consolidated areas will be found around 
the bronchial space, infiltrating in all directions and with- 
out definite boundaries. A similar lesion has been seen 
also in the liver on rare occasions, but the lung is its usual 
seat. Judging from microscopic appearances this is a 
process complicated by the addition of bacteria. 
The third variety is nodular or tubercular mycosis, a 
process of probably more chronic nature since around the 
isolated lesions connective tissue is perceptible, it being 
absent or inconspicuous in the other types. The 
formation of gray or yellow-white nodules from a few 
millimetres to a centimetre in cross section, is the charac- 
teristic production in this variety. Lungs, liver, spleen, 
intestines and air sacs are involved in about this order. 
Attempts at explanation of this peculiarity of growth 
were made in the direction of identification of the species 
of mould, kind of bird and probably degree of resistance. 
No conclusions could be drawn since the same variety of 
mould was found in this as in other types ; no bird showed 
a special susceptibility or resistance to it. It is quite 
difficult to obtain a culture from nodular mycosis, it being 
necessary to crush or grind the solid masses before 
making cultural implants. This variety should always 
be differentiated from tuberculosis by staining for 
the organisms. 
Histologically studied these three types are not as 
easily separated as the gross appearances would warrant 
one to expect. The original mould nodule begins in 
essentially the same manner in all, a small colonization 
of mycelia and spores which grow centrifugally, but ever 
becoming more intricately wound in their first location. 
As the tissue is invaded, total necrosis takes place, no 
recognizable cellular architecture being left. When fully 
formed the mycotic tubercle consists from the centre 
outward of a necrotic mass, in which spores and mycelia 
