Essed . — The Panama Disease. /. 
349 
also. In yet another case a yeast-like budding took place, giving rise to 
a promycelium, which may laterally and apically throw off conidia or grow 
into a dark-coloured mycelium as met with before (see PI. XXVIII, Fig. 7). 
The chlamydospores may arrange themselves in beadlike fashion ; 
some of the spores then emit germ tubes, which grow at once into a myce- 
lium ; others produce promycelia with conidia or conidia alone. Finally 
they give rise to branched promycelia, on which chlamydospores and conidia, 
arising on the extreme tips of the branches, put a stop to their further 
development (see Fig. 8). 
The oidia did not differ in their mode of germination from the first- 
mentioned kind of gemmae, with which they are, in fact, identical, as 
could indeed be inferred from their mode of origin (see Fig. 8). 
The bicellular conidia produced branched mycelia, which grew out at 
one or both ends ; but in some cases fusion was seen to occur between two 
of these conidia; one of them assumed the nature of a chlamydospore, 
giving rise to a branched promycelium with conidia constricted off at the 
apices of the hyphae. 
The Fusarium conidia, germinating under ordinary conditions, did not 
present any essential difference. The mycelia mostly arose on the apical 
cells, each giving off sometimes two germ tubes. But in many cases the 
protoplasm was drawn to one or two of the cells, which rounded off and 
then germinated exactly as the gemmae. The same transformation of 
Fusarium conidia into gemmae was noticed on an old culture, where, after 
two months, these conidia were replaced by gemmae ; this surely throws some 
light on the occurrence of gemmae in the pycnidia and the prominence of 
the chlamydospore fructification in general. 
The multicellular chlamydospores or gemmae presented the same 
peculiarities in germinating as mentioned in the case of the single cells. 
Bits of sclerotium were seen showing a differentiation into spores ; 
after a few days they were formed, still enveloped in mucilage. As soon 
as the mucilage was resorbed they started germinating in the same way as 
mentioned under chlamydospores. In another bit, germ tubes arose in the 
still undifferentiated mass as stout, highly refractive rods, which gradually 
emerged from the sclerotium, producing promycelia as before (see PI. XXVI 1 1, 
Fig. 8). This goes to show that the sclerotium is able to propagate the 
fungus in the same way as the chlamydospores. Another function of the 
sclerotium is made plain in the following account of the formation of what 
I think I am justified in considering a fruit body; for although it was not 
obtained under sterile conditions, and its premature withering prevented 
me from controlling my conclusion by raising new mycelia from the asco- 
spores, it is plain that the identical Fusarium conidia and gemmae could 
not arise except on a part of the fungus under investigation. 
A sucker of the banana in the second stage of the disease, from which 
