72 BOTANICAL GAZETTE [ AUGUST 
color; at the margin of the spot the pustules are frequently 
arranged in concentric circles. 
Sections of the fruiting bodies show the extreme variation 
marked by Miss Southworth. The developing stroma at the 
base of the pustule causes in some a depression in the tissue of 
the host, which is shrunken and brown for some distance down 
in the fruit. In others there is scarcely any depression; the . 
base of the pustule is very narrow, and the basidia, which 
become septate with age and quite dark in color, spread gradu- 
ally and extend a considerable distance above the host, giving 
the pustule in cross section a flabellate appearance. In the 
older pustules the disappearance of the basidia at the center was 
observed, and in addition to the ordinary conidia, on some of 
the elongated basidia were borne large oval or club-shaped 
bodies which become fuliginous, and are single-celled or once 
septate. They resemble the so-called secondary spores so fre- 
quently observed in artificial cultures. The conidia are hyaline, 
single-celled, elliptical, ovate or sometimes curved, varying con- 
siderably in size and shape. i 
In a dilution culture of meat-, or potato-agar, the conidia 
germinate readily within three or four hours. A germ tube 1S _— 
developed usually near the end of the conidium, which becomes 
coarsely granular and the contents begin slowly to pass into the 
tube. Two or three germ tubes frequently arise from the conid- 
ium. Sometimes the conidium upon germination becomes | 
septate, but this is the exception under favorable conditions of 
growth. The fusion of the conidia mentioned by Mr. Alwood? : 
is not peculiar to the species, but is frequently seen in other 
species, and is apparently due to a lack of nutrition, as it is most 
noticeable in water cultures or in agar-agar cultures when the 
growth is crowded, or when the nutritive material is exhaustel 
Within two or three days after sowing is made, the small te . 
late colonies may be seen in the agar with the unaided ey® 2 
They are subcircular or elliptical, the center being marked ke, . 
slightly elevated, more compact growth of mycelium, elong® . ae 
4 Loc. cit., 67. 
