108 MISSOURI BOTANICAL GARDEN. 
fruiting bodies are usually borne at or above the surface of 
the a upon which it is cultivated. The following is 
a résumé of the cultural characters of the fungus :— 
MYCELIUM. 
The spores of the fungus germinate in a very short time, 
usually a few hours, and in thirty-six hours small white 
colonies are visible upon the surface of agar media. The 
first mycelium that forms is rather sparse, but thickens as 
the colony grows older. Two types of conidia are borne 
on the fertile hyphae, which are formed in a short time 
after germination of the spores. These are the micro- 
conidia (pl. 12, f. 1, 2,3), which are found very numerously 
in all parts of the mycelium, except in the newest growth, 
and the macroconidia (pl. 12, f. 4, 5), which are found 
sparsely only in the older portions of the mycelium. 
Chlamydospores are formed abundantly i in all the older 
portions of the colony about the time the growth of the 
mycellum is checked by a limitation of nutrition, being 
formed usually with or a little later than the macroconidia. 
The anastomosing of filaments is quite frequent (pl. 12, 
£..8). 
MICROCONIDIA. 
Microconidia are formed in great numbers on various 
vegetable media, such as agar media made with plant decoc- 
tions. They are usually borne on hyphae which branch 
alternately from the mycelium. They are formed by the 
abstriction of the ends of hyphae, and where they are not 
disturbed by air currents or some sudden shock, they 
adhere to each other side by side in clusters which assume 
a form of fruiting resembling Cephalosporium (pl. 12, 
f. 3). These microconidia are at first one-celled. A sep- 
tum is often formed before the spore becomes detached 
from the hypha, and later many of the one-celled conidia 
that have fallen off form septa. The two-celled form 
