1906} HASSEL BRING—AI PRESSORIA OF ANTHRACNOSES I4t 
To test the resistance of spores to drying after being freed from 
the surrounding mucilage by washing, a quantity of spores was 
shaken up with water and then spread out on glass slides which 
were allowed to dry. After remaining dry 14 hours, few spores 
germinated when again placed in water; after 24 hours, none ger- 
minated. At different times during the summer spores were shaken 
up in water and sprayed on filter paper, apples, and glass slides, but 
it was impossible to cause them to germinate after having been 
dried 24~30 hours. 
That the appressoria are more resistant is shown by the following 
experiment. Appressoria were produced by sowing spores in drops 
of water on slides 
which were kept in a sc... 
moist chamber until jf ge 
the following day. {| 
The slides were then 
allowed to d SHA. \ 
ry, all f | 
a submerge fos Seis 
d spores 
Fie Fics. 5, 6.—Natural appressoria 
formed on the surface of apples. 
Fic. 7.—Section showing relation 
of adhesion organ to cuticle of apple. 
having produced appressoria. 
The germination of the appres- 
soria was tested from time to 
time by covering a slide with 
sugar-beet infusion. The ap- 
inesulanl pressoria germinated, though 
= arty, as late as Dec. 11, when the last slide was used. 
oe the hot summer weather the bitter-rot spores germinate 
bate is vis In 12-24 hours the appressoria are formed. Under 
diately . itons the germ tube is extremely short, since it imme- 
ret 2 ss to the formation of an adhesion-disc. From this 
sabes sa nea and more resistant organ the infecting hypha dis- 
any chils e into the fruit. In badly infected trees the appressoria 
€ found in great numbers adhering to the surface of the 
