50 BULLETIN 727, U. S. DEPARTMENT OF AGRICULTURE. 
286). Thelateral walls are thin except for a rodlike thickening extend- 
ing from base to apex of each cell. The processes of fermentation 
and washing remove all of this cell layer except these rodlike thick- 
enings, most of which remain as cellulose hairs (fig. 15). These 
hairs become closely appressed to the seed when the latter is dry 
and may protect adhering spores or appressoria from extreme 
desiccation. Furthermore, since the fungus may be present in the 
adhering fragments of fruit tissue it is evident that in this form 
desiccation could be more readily endured. 
It is scarcely believed at present that the fungus will survive an 
additional ‘year’s storage, and hence it is only reasonable to main- 
tain that the disease is introduced only with seed planted the year 
after it is harvested. This is an important consideration, since in 
practice much of the cucumber and melon seed is more than a year 
old when used. Cucum- 
y ber seed is known to re-. 
main viable from two 
There is also the pos- 
sibility of internal car- 
riage of dormant myce- 
lium within the seed. 
Eriksson (16, p. 127), 
after failing to find my- 
Fig, 15,—Cross section through the seed coat of acucumber seed, celjym in supposedly 
showing cellulose rods, or ‘‘hairs.’’ 
( 
COND 
infected seed, advances 
his mycoplasm theory to account for anthracnose carriage in cucum- 
ber seed. The depth of fruit lesions as observed on seed cucumbers 
and watermelons suggests that seed infection may occur previous to 
seed extraction. From observations made upon seed cucumbers col- 
lected in October, 1917, it appears that there may be considerable 
opportunity for the internal infection of seed. Coalescent lesions 
were found penetrating the placentz as far as the seed, and in some 
instances the gelatinous capsules were decomposed and the funiculi 
rotted off at the points of attachment to the seeds. 
Samples of seed removed from beneath such lesions were tested 
in two ways for the presence of the anthracnose fungus. The seeds 
were sterilized in mercuric chlorid, 1 to 1,000, for five minutes, washed 
in sterile water, and some were planted intact in poured plates of 2 
per cent dextrose agar. From others the embryos were aseptically 
removed and planted in similar plates. Tests were made on Novem- 
ber 4 and December 14. In 87 seeds tested by the former method 
and 90 by the latter no trace of the anthracnose fungus was obtained. 
to six years, and many 
, erowers prefer old seed. 
\ POSSIBILITY OF INTERNAL CAR- 
RIAGE OF MYCELIUM. ; 
JON, 
—_—— _ 
