74 BOTANICAL GAZETTE [july 



(fig. 2) in the stimulated seedlings. These latter become the 

 concave and convex halves (fig. 3) respectively in the responded 

 organ. Samples varying from 6 to 10 gm. were used. The fresh 

 portions were weighed in weighing bottles and the weight obtained 

 by difference. The tissue, thus obtained, was cut up fine and 

 triturated, killed in boiling 85 per cent alcohol, and boiled for 

 30 minutes. 



The triturated tissue was subjected to alcoholic extraction for 

 3 hours and to ether extraction for 2 hours in the Koch modification 

 of the Soxlet extractor. The tissue was then pulverized and 

 extracted in boiling water 30 minutes. This water extraction was 

 repeated six times. Following this was another alcohol extraction 

 of 24 hours. The original killing alcohol, the ether extract (the 

 ether was evaporated and the extract brought into solution in 

 water), the water extract, and the two alcohol extracts were com- 

 bined, and the volume increased to 500 cc. by the addition of water. 

 This extract contained all the material soluble in these solvents, 

 that is, the sugars, the lipoids, and the amino acids, and may be 

 designated F x . The residue contained the insoluble substances 

 (starches, pectins, hemicelluloses, and cellulose), and may be 

 designated F 2 . From F x was taken three 150 cc. portions for the 

 determination of (1) sugar, (2) nitrogen, and (3) dry weight. From 

 F 2 was obtained (1) the dry weight and (2) the hydrolyzable poly- 

 saccharides. 



The alcohol-water-soluble portion for the determination of 

 sugar was freed from alcohol by evaporation on the steam bath, 

 water being added before and during the process of evaporation, 

 and the final volume brought to 150 cc. The tannins and lipoids 

 were precipitated by the addition of a 10 per cent solution of 

 basic lead acetate, the volume made up to 200 cc. and filtered 

 immediately. The excess lead was precipitated from 150 cc. of 

 the filtered solution by means of a saturated solution of ammonium 

 sulphate, and the volume brought again to 200 cc. Duplicate 

 determinations of 50 cc. portions were made of sugar solutions thus 

 obtained, by the Munson and Walker method for the determination 

 of reducing sugars (17). The amount of cuprous oxide thus ob- 

 tained was determined by the volumetric potassium permanganate 



