28 
Journal of Agricultural Research 
Vol. VII, No. i 
are 39.3, 44.3, and 47.6 mgm., and since these amounts may fairly be con¬ 
sidered as the nitrogen of proteins, the employment of the factor 6.25 gives 
245.6, 276.8, and 297.5 mgm. of protein for the three lots of tissue, or a 
gain of 51.9 mgm. of protein in the course of the process of decay. This 
unquestionably represents the synthesis of protein by the attacking 
fungus. It may be further pointed out that the gain in nitrogen in frac¬ 
tion 3 is not sufficient to account for the decrease in fraction 2; only about 
two-thirds of the 11.67 mgm. lost from fraction 2 by completely decayed 
tissues is represented by the gain of 8.3 mgm. occurring in fraction 3, and 
the total nitrogen figures are 60.3 mgm. for sound and 56.93 mgm. for 
completely decayed fruits, indicating a slight loss of nitrogen. Determi¬ 
nations of ammonia made upon aliquot parts of fraction 2 immediately 
upon completion of the separation showed a slight decrease in the amount 
present as the disease progressed; for sound tissue the figures were 3.757 
mgm. of ammonia; for partially decayed tissue, 3.620 mgm.; for entirely 
decayed tissue, 3.485 mgm. Although these differences are small and 
subject to a relatively large experimental error, as must always be the 
case when extremely low concentrations of ammonia are determined, they 
nevertheless are concordant and compel the conclusion that the peptone 
and amino nitrogen of the fruit are steadily decreased with the progress 
of the disease by two processes, one a degradation process which results 
in the formation and escape of ammonia, the other an anabolic process 
which converts the soluble nitrogenous constitutents into insoluble forms, 
presumably within the cells of the invading organism. Reed and Stahl 
(21) reported the presence of erepsin in cultures of Sphaeropsis malorum , 
as evidenced by the formation of tryptophane from the peptone of Dun¬ 
ham's solution, but no further studies of the proteases of the genus 
Sphaeropsis appear to have been made, although Reed (18) has recorded 
the presence of an amidase able to form ammonia from alanin and aspar- 
agin in Glomerella rufomaculans . 
Many of the statements made in the preceding discussion are rendered 
conclusive by inspection of the data for phosphorus. In the normal 
fruit the distribution of phosphorus between the three fractions is as 
follows: Lipoid fraction 30.25 per cent, water-soluble portion of alcohol- 
ether-water extract 57.22 per cent, and the insoluble portion 12.53 P er 
cent. In the half-decayed fruits there is a very marked decrease in the 
insoluble fraction from 12.53 to 6.12 per cent; a less marked decrease from 
30.25 per cent to 27.40 per cent in the lipoid fraction, and a concurrent 
gain in water-soluble phosphorus from 57.22 to 66.48 per cent of the 
total. These figures show that in the earlier stages of the attack the 
changes which involve phosphorus are predominantly katabolic in 
nature, and that they affect both lipoid and protein phosphorus, reducing 
both to simpler water-soluble forms. With the further progress of the 
disease, there is a further reduction of lipoid phosphorus to 25 per cent, 
