34§ 
Essed . — The Panama Disease . L 
at the summit of thick, short side branches, or intercalary as in Entyloma. 
On the eighth day the conidia made their appearance on the hyaline parts 
of the mycelium ; but few sclerotia were formed. From the tenth day 
onwards no real change was perceptible until, in the fourth week, the 
mycelium broke up into a dense mass of chlamydospores. At all events, it 
was shown that the difference of colour of what appeared to be two distinct 
kinds of mycelia was only due to a slight modification of the nature of the 
spores from which they arose. 
Cultures on gelatine medium. It was not easy to produce a solid 
gelatine medium on account of the high temperature reigning in the tropics. 
Still, the mycelia raised in the semi-fluid medium excellently established 
the facts gathered from the agar cultures. One special feature of the 
gelatine cultures, however, was the appearance of the hyaline, bladder-like 
structures already described as haustoria. They arose and remained sub- 
merged in the semi-fluid medium, performing their haustorial function. 
Comparing the results of the histological research with the facts gathered 
from the pure cultures, one cannot fail to see the identity of the structures 
found in the plant tissues and those developed on the Petri dishes. The 
figures will fully explain the matter. 
Cultures in Life-box. 
From one of the most flourishing cultures a sufficient quantity of 
mycelium was transferred with the aid of a sterile, spatulate platinum wire to 
a tube containing + io grains of sterilized water and divided by agitating 
moderately. A drop was brought on a thoroughly clean cover-slip, a drop 
of sterilized water placed on the bottom of the life-box, and the cover-slip then 
fixed on by means of some vaseline. Three other life-boxes were prepared 
for the sake of comparison. As a matter of convenience in describing the 
different modes of germination, I shall take the liberty of making some 
distinction between chlamydospores, gemmae, and oidia. By chlamydospores 
I designate the spores arising from the sclerotia ; by gemmae, those formed 
in the course or at the apices of fertile hyphae ; and by oidia, the spores 
which are set free by the breaking up of the fertile hyphae into the 
component, isodiametric cells. 
The gemmae were the first to germinate ; some gave rise to short, 
club-shaped tubes, at the apices of which one or two small conidia were 
cut off; another group grew tubes of 3-7 cells, small bicellular conidia 
arising apically and laterally. These conidia were often loosely joined 
together in pairs or in bundles of three or more, the adherence probably 
being caused by a thin layer of mucilage enveloping them. In another case 
the conidia were thrown off by the gemmae at once, without the interpola- 
tion of a promycelium, reminding one of the germination of Entyloma , 
which very often takes place on the host plant, as could be seen in this case 
