92 Journal of Agricultural Research voi. vi, no. 2 



It should be stated with reference to the data presented in Table III 

 that the figures given are the weights in grams of the several constitu- 

 ents as determined by employing 27.25 gm., fresh weight, of healthy and 

 of cankerous tissue. Since the two samples differed by only 3 mgm. 

 in dry weight and since the figures, to be directly comparable, should 

 be based on dry weights in each case, a correction of 0.24 per cent should 

 be applied to the analyses of diseased tissue. As this is insignificant, 

 the data are regarded as referable, and the corrections have not been 

 applied. 



Because of the presence of certain enzyms, of which mention has been 

 made earlier in this paper, it is to be expected that the changes of great- 

 est magnitude would occur in the carbohydrates. That such is the 

 case is obvious when one notes in the totals given in Table III a reduc- 

 tion of all classes of carbohydrate in cankerous tissue. Thus, in equal 

 quantities of fresh material the amounts of reducing sugar are found to 

 be as 5 to 2, the total sugars as 3 to 2, and the polysaccharids as 5 to 3 

 when normal and diseased tissues are compared. Because of the ease 

 with which they are available to the invading organisms, the reducing 

 sugars are probably the most strongly attacked. After acid hydrolysis 

 the normal tissue shows more reducing sugar than the diseased, both in 

 the alcohol-ether soluble and alcohol-ether insoluble fractions. This 

 means that there is also a less amount of the higher soluble carbohydrates, 

 disaccharids, in diseased tissues and that they too are more easily avail- 

 able than the polysaccharids. The ratio of disaccharids in normal and 

 cankerous tissue in the alcohol-ether soluble and alcohol-ether insoluble 

 portions is as 3 to 2 and 5 to 3, respectively. 



There is also a slight but significant decrease in the amount of cellu- 

 lose found in diseased tissues. Although the difference in total cellulose 

 in the normal and diseased tissues is slight, the results given are repre- 

 sentative of a considerable number of determinations in which two 

 standard methods were employed and in which the lesser amount of 

 cellulose was invariably found in the diseased tissue. Experimental 

 error has thus been eliminated and the results indicate a slight but un- 

 mistakable destruction of cellulose by the invading organisms. 



The polysaccharids were determined in fraction 3 after 2.5 hours acid 

 hydrolysis. They were found to be present in normal tissues and dis- 

 eased tissues in the same proportion, 5 to 3, as were the disaccharids. 

 There has therefore been a corresponding reduction and utilization of 

 both di- and poly-saccharids by the invading organisms. 



In the alcohol-ether insoluble fraction the amounts of nitrogen found 

 for normal and diseased tissue were 0.105 and 0.0818 gm., respectively. 

 If the conventional factor for these figures, 6.25, is employed, 0.654 and 

 0.511 gm. are obtained as the protein content of normal and diseased 

 tissues, respectively. The protein content of diseased tissue has there- 

 fore been reduced 78.16 per cent. One should therefore expect to find a 



