1^8 BOTANICAL GAZETTE [February 



^o 



Dry weight. — One- tenth or one- twentieth ahquots, in tared 

 crucibles or beakers, were brought to constant weight in a vacuum 

 desiccator after intermittent drying for various lengths of time at 

 about 1 00° C. 



Nitrogen. — Estimations were made by the Kjeldahl-Gunning 

 method, modified to include the nitrogen of nitrates. For healthy 

 samples i and 2 and diseased samples i and 2 estimations were 

 made separately on fractions 2 and 3; no nitrogen was found in 

 fraction 2. Estimations for healthy samples 3 and 4 were made 

 on one-twentieth of the alcohol extract combined with one-twentieth 

 of the partly extracted bark. 



Carbohydrates. — Healthy samples i and 2, diseased samples i 

 and 2 : in the case of fraction 2, direct reducing sugars, and reducing 

 sugars after mild hydrolysis, were estimated by the Bertrand 

 volumetric method and calculated as dextrose by use of the Munson 

 and Walker tables (34) . The more important details of manipula- 

 tion, including precipitation of non-sugars, are given by Cul- 

 pepper, Foster, and Caldwell (16). The polysaccharides in 

 fraction 3 were estimated as dextrose, but after 2 . 5 instead of 

 5 hours' hydrolysis (16). 



Healthy samples 3 and 4: one-twentieth of the air dry, partly 

 extracted bark was further extracted on a filter with about 200 cc. 

 of water at 40° C, the filtrate being collected in a beaker containing 

 one-twentieth of the alcohol extract. Estimation of sugars and 

 polysaccharides in the combined extracts were then made as 

 already described. The results of the analysis are given in tables 

 XXIII and XXIV and summarized in table XXV. 



The most important differences shown in the tables, as between 

 healthy samples i and 2 and diseased samples i and 2, are as fol- 

 lows: diseased tissue contains 3 . 23 per cent more dry matter than 

 healthy, although here much depends on the manner in which the 

 sample is taken; on the basis of dry weight, fraction i is larger 

 in the diseased by 4.56 per cent (nearly doubled), indicating a 

 synthesis of lipoids by the fungus; fraction 3, the alcohol- water- 

 insoluble residue, is larger by i .83 per cent, while fraction 2, con- 

 taining the alcohol-water-soluble substances, is smaller by 6.27 per 

 cent. These results are strikingly similar to those found by 



