102 



fering with the proper translocation of foods to rapidly grow- 

 ing parts would permit an abnormal development of oxidases and 

 a consequent yellow or diseased condition." Woods^^ discovered 

 that oxidases, when acting in the sunlight, have the power to 

 destroy chlorophyll and cause yellow spots on leaves; a condi- 

 tion noted on the foliage of the Bermuda lily, carnation, tomato, 

 etc. Punctures of leaves by insects- or the presence of parasitic 

 fungi, most of which contain oxidases, result in the decomposition 

 of chlorophyll and the production of such yellow spots. Oxi- 

 dases may exist in the soil or plant remains for several months, 

 and thus cause infection if the new plants are not in a healthy 

 condition. Recently Hasselbring and Alsberg^^ found that there 

 is a disease of cabbage and spinach somewhat like the " mosaic 

 disease" of tobacco. They also noted an apparent increase of 

 oxidase content in the diseased spots, but thought this result 

 might be caused by a decrease of anti-oxidases in the affected 



area. 



Experimental Part 



The historical part of this paper makes it evident that there 

 has been no lack of effort to determine the distribution and 

 nature of the oxidizing enzymes. However, many previous in- 

 vestigations were carried out with the use of but one reagent, 

 which was generally guaiac tincture; besides, adequate checks 

 upon the reagents or upon the plant juices were not made. Any 

 one familiar with the use of the oxidase reagents realizes that the 

 most sensitive of them, such as the indo-phenol reagent and 

 phenolphthalln, are so easily oxidized that constant care must be 

 taken that the action of atmospheric oxygen be not interpreted 

 as a positive test for a weak oxidase. Furthermore, in all in- 

 vestigations involving the use or comparison of colors, one must 

 be alert to detect differences due to a personal factor or to the 

 illumination. Our investigation was undertaken with the 

 purpose of examining and extending previous work upon the 

 distribution of the oxidases; studying the conditions of their 

 activity, and their effects upon different reagents, etc. 



" Woods. The Destruction of Chlorophyll by the Oxidizing Enzymes. Central- 

 bit, f. Bakt. II Abt. 5: 745. 1899. 

 5* Hasselbring and Alsb^rg, Iqc. cit. 



