24 MISSOURI AGR. EXP. STA. RESEARCH BULLETIN NO. 21 



It should be mentioned here that all the observations on colors 

 were corroborated by the judgments of two or three persons who 

 knew nothing about the details of the experiment. 



To make the results comparative, seven easily recognized colors 

 were taken as a standard. Water color reproductions of these are 

 shown in Fig. 7, in the order in which they may be obtained. Each 

 color was numbered beginning with 1 and ending with 7. These 

 numbers are used in the tables. The smaller the number, the less 

 the enzyme activity; the greater the number, the more active the 

 ferments. (See Fig. 7, p. 63). 



That the changes occurring in the experiments were due to 

 enzymes contained in the tissue was taken for granted from the fact 

 that whenever the tissue was heated to 100 C. for a few minutes 

 and then allowed to act on starch paste, no change occurred. The 

 reaction with iodine was the characteristic blue thruout the time 

 of the experiment. The rapid conversion of the starch 1 and the fact 

 that toluene was added to prevent organisms from developing, 

 eliminates bacterial activity as being responsible for the changes 

 noted when unheated material was allowed to act. 



This method of determining the comparative enzyme activity 

 is, of course, not free from objections. A probable source of error 

 is found in the fact that many substances were dissolved from the 

 tissue in addition to the enzymes. Some of these substances, e. g., 

 tannin may hinder to some extent the free action of the enzymes. 

 However, it is likely that the same amount of these inhibiting factors 

 were present in both check and treated material, so that the com- 

 parative value of the results remain unaffected. Again, the results 

 were not as quantitative as might have been desired. On the whole, 

 however, the methods outlined gave very satisfactory results for 

 these preliminary experiments. The simplicity of the tests and the 

 reliability of the results are points in favor of the method. 



The results obtained with the diastatic enzyme experiments 

 are summarized in Tables 7 to 11. In all cases, the dates show when 

 the material was collected. Enzyme activity was determined after 

 two and after four hours. This activity is expressed in numbers 

 which are based on color reactions as previously explained. It should 

 be kept in mind that the greater the number, the greater the enzyme 

 activity. The plus sign after the numbers indicates that the color 

 was close to the next more advanced; the minus sign indicates that 

 the color barely passed the less advanced. For example, 2 and 



1. Bayliss, W. W. The Nature of Enzyme Action. (Longmans. Green, 

 & Co. 1911). 



