542 REPORT OF THE HoRrTICULTURIST OF THE 
b 
nearly colorless and showed no pink tint. According to Frank* ‘ 
the spores fall on the surface of the host and send out a germ 

tube which presses its enlarged end closely against the epidermal Bs" sak 
cells. From this a colorless hypha penetrates the cell walls and 
grows into a mycelium which fills the cell cavities. Then the 
mycelium penetrates into the underlying tissues.§ “Almost 
immediately the cell walls of the host and their contents become 
discolored and in the exocarp the cell walls collapse, thus forming — 
an almost solid mass of cell walls and mycelium.” Fig. 3 illus- 
trates a section of the pod through the collapsed tissue which 
underlies a cluster of basidia. The epidermis which formerly 
covered the acervulus has broken away and a portion of its 
recurved edge is seen at the right. A seta is also shown projecting 
peyond the acervulus, and a few spores remain attached to the ends 
of the basidia. The collapsed tissue is seen below. By the 
collapse of the tissues the anthracnose pits are formed. In the 
leaf parenchyma, as previously stated, the tissue becomes collapsed | 
and brittle, so that rifts through the leaf soon form in the center 
of diseased spots. 
The basadia are upright (perpendicular to the stroma) and 
unbranched. Associated with them are a few setae which when 
mature are long and of dark brown color. Sometimes the setae 
are septate and sometimes they arise from a many-celled bulbous 
base. 
The conidia are illustrated in Fig. 4. They vary in length from 
11.5u to 18~ and in diameter from3.7u to 5.3u. An average of 
sixteen measurements gave the following dimensions: 15.2% x 
4.4% They are non-septate, hyaline, oblong, cylindrical or some- 
times slightly narrowed towards one end. They burst through. 
the epidermis in masses held together by some substance which 
soon dissolves in water. 
The fresh conidia may be germinated readily in sterilized broth 
made from bean pods or foliage. They germinate less readily in 
sterilized water. Germination usually begins at or near the 
extremities of the spore, and two or more s¢erm tubcs may ‘issue 
from one spore. Figure 5 illustrates the progress of gerinination - 


* Deutschen Botanischen Gesellschaft, Berichte der, Band 1, 1888, pp. 31-34, 
§ U. 8. Dept. Agr. Report, 1887, p. 363. 
Sy 

