Apr. lo, i9i6 Citrus Canker 93 



very material increase in the nitrogen of the alcohol-ether soluble portion 

 of the diseased tissue. This expectation is realized, since the nitrogen 

 figures for the soluble portions are 0.1386 gm. for normal and 0.7806 gm. 

 for diseased tissue. This represents an increase in the diseased tissue 

 of 37.52 per cent over the healthy tissue. This increase in the soluble 

 portion indicates a decomposition of the complex nitrogenous compounds 

 resulting in the formation of peptones and amino acids soluble in alco- 

 hol and ether. This difference in nitrogen content of the alcohol-ether 

 soluble portion takes an added significance when the nitrogen content of 

 fraction i and that of fraction 2 are examined separately. It will be 

 recalled that the nitrogen of fraction 2 represents those portions of the 

 nitrogenous constituents extracted by alcohol and ether which are readily 

 soluble in water after the combined extract has been evaporated to a 

 paste. They are, therefore, amino acids and polypeptids. It will fur- 

 ther be recalled that fraction i is obtained from the watery solution of 

 the alcohol-ether soluble extract by chloroform precipitation and is there- 

 fore lipoid nitrogen. The slight decrease in nitrogen in fraction 2, when 

 normal and diseased tissue are compared, is accompanied by an enor- 

 mous increase, amounting to 250 per cent in the lipoid nitrogen of 

 fraction i. 



These differences in nitrogen content of the several fractions lend 

 themselves to two possible explanations. The first and most obvious 

 interpretation of the results is that the changes produced by the invading 

 organisms in the proteins of the host result in the formation not of 

 amino acids and other end products of protein decomposition but in the 

 production of complex intermediate substances. The other explanation 

 is based upon the fact that the bacteria themselves derive the nitrogen 

 necessary for the building of their own proteins as well as for the forma- 

 tion of their cell walls from the proteins of the host. Concurrently 

 with the reduction of the protein of the host to simpler forms a series 

 of metabolic processes is occurring within the invading organism which 

 involves the synthesis of these simple nitrogenous compounds to more 

 complex ones. The changes in nitrogen content of the several fractions 

 of the diseased tissue are therefore the result of both analytic and 

 synthetic processes. At present it is impossible to employ any methods, 

 as none have been devised, which will indicate what the end products 

 of decomposition of the host proteins by the invading organism are, 

 since the formation of these products is accompanied by their con- 

 comitant utilization in the manufacture of new compounds peculiar to 

 the body of the parasite. 



The total phosphorus in the diseased tissues is greater in amount in 

 fractions 2 and 3 than in the normal tissues. Were the changes in the 

 diseased tissue purely katabolic, it would be expected that there would 

 be a material increase in water-soluble phosphorus derived from the 



