iqiq] KNUDSON b- SMITH— AMYLASE 463 



cultures were grown in a greenhouse, under favorable conditions, 

 from November 14, 1916, to December 5, 1917. One of the cultures 

 became contaminated, so that data were obtained from only one cul- 

 ture. Reducing sugar was determined by Kendall's method (i). 



The dry weights of roots and tops were respectively 172 and 

 430 mg. ; the total weight was 602 mg. ; and the increase in weight 

 over the original weight of the seed was 262 mg. Determinations 

 made of the reducing sugar in 100 cc. lots of both the culture solu- 

 tion and the control solution gave 22.18 mg. of copper for the 

 former, and 11 .25 mg. for the latter; or an increase of 10.93 i^g- 

 of copper for a 100 cc. solution (about 6 mg. of maltose). A 

 sample of the culture solution and one of the control, with 2 per cent 

 of toluene added to each, were incubated for one week at 30° C, 

 and showed no increase in reducing sugar. 



In this preliminary experiment there was noted a slight increase 

 in reducing sugar, but the increase was so small as to be without 

 significance. Furthermore, the fact that there was no increase of 

 reducing sugar on incubation leads to the conclusion that the 

 enzyme amylase was not secreted into the culture solution. 



The conditions of the second series of experiments were the 

 same as for the preceding, except that liter flasks were employed 

 as culture vessels, and iioocc. of the culture solution was used. 

 A variety of white dent corn known as Boone County White was 

 used. The cultures were grown for a period of 51 days. 



At the conclusion of the experiment, the culture solutions were 

 brought to their original volume and samples were kept for analysis. 

 To the sample solutions was added 2 per cent of toluene, and two 

 weeks elapsed before the solutions were analyzed for reducing 

 sugars. Analyses were made by the Munson Walker method. 

 Data are given in table I. The data indicate that in the culture 

 solutions there is a slight increase in reducing sugars, but not 

 sufficient to warrant the conclusion that there is any amylase 

 secretion. The objection might be raised that in these cultures 

 there can be no accumulation of reducing sugars, because they are 

 utilized as fast as produced, which is possible; but the fact that 

 the increase is so slight, even after two weeks of incubation, sup- 

 ports the theory that no amylase was present. 



