Essed. — -The Panama Disease. II. 
358 
the proteids in the protoplasm — the nucleus is not attacked, at any rate 
not primarily — was also the cause of the dissolution of the hyphal walls, 
which mainly consist of chitin, an albuminoid. In trying to prove this, 
I found that the action on the hyphal walls was very much enhanced when 
a few drops of \ % HC1 were added to the solution of the enzyme. I have 
satisfied myself as to the absence of any action of % HC 1 alone. The 
change, however, was very slow in manifesting itself, and was not perceived 
sooner than on the eighth day, when the walls were found to gradually 
change into a highly refractive gelatinous mass. Along with this a large 
number of crystals of calcium oxalate were seen to be secreted, throwing 
light on the presence of the same in the tissues of the banana attacked by 
the fungus. 
The coincidence of the softening of the hyphal walls, i. e. the secretion 
of enzyme, with the chlamydospore and pegmatium formation, gives a plau- 
sible explanation of the outbreak of the disease at the time of prominent 
seasonal changes, from drought to wet weather and vice versa , since chlamy- 
dospore-formation takes place when plenty of moisture is present and peg- 
matia arise when the water supply is limited, as was alluded to before. 
The hyphal ivalls are composed nearly entirely of chitin, which was 
found in the following way : Pure cultures were raised on sterilized liquid 
banana extract in tubes of 3 cm. diameter. At the close of a fortnight 
a mycelium covering the surface of the liquid was removed to a dish of 
distilled water and well washed out so as to remove the adhering extract, 
and then transferred to a tube with Schweizer’s reagent. It was left for 
four days, agitated from time to time. Removed from the solution, it was 
again thoroughly rinsed and left for four days in % NH 4 OH, which 
was changed every day ; washed out and dried in the stove at a temperature 
of 40° C. Brought under the microscope, not the least change could be 
detected, giving reason to infer the absence of cellulose. A fragment ot 
200 mg. was heated with KOH solution and subsequently treated with 
dilute H 2 S 0 4 , 95 % alcohol and ether. A transparent horny substance was 
obtained of the same shape as the original material. When heated it was 
carbonized without preceding fusion. Other fragments proved to be only 
soluble in concentrated mineral acids and eau de Javelle, quite easily when 
heated ; in this case the mycelium was carbonized before dissolution in 
H 2 S 0 4 . The solution in hot HC 1 was evaporated till dry, when hygro- 
scopic needles of glucosammonium chloride were seen to arise, which, dis- 
solved in water and treated with KOH, gave rise to a precipitate of 
glucosamine. Another fragment was heated with alcoholic KOH solution 
and the mixture allowed to cool. The supernatant liquid was decanted 
and treated with dilute HC1 in slight excess, when a comparatively small 
quantity of a gelatinous substance was thrown down, which, with the aid of 
staining methods recommended by Strasburger, proved to be pectine. 
