220 EXPERIMENT STATION EECORD. 



The investigations led to the couc-lusion that although oxidase is more widely 

 distributed than chromogen, the distribution is in conformity with that required 

 by the oxidase chromogen hypothesis. Owing to the existence of inhibiting 

 substances, caution must be exercised in interpreting the negative results ob- 

 tained by the use of oxidase reagents as proof of the absence of oxidases. 



In considering the presence of oxidases in flowers, oxidase was found present 

 in the petals of all colored and recessive white varieties of P. sinensis. The 

 dominant white varieties contained an inhibitor of oxidase, the removal of 

 which was followed by a strong oxidase reaction. Ever-sporting varieties of 

 primulas and sweet william showed the most epidermal oxidase in the deeply 

 pigmented flowers, less in those less highly colored, and none at all in the white 

 flowers. Albino forms of primula, peas, and sweet peas all were found to con- 

 tain oxidase, and their floral albinism is attributed to lack of chromogen. The 

 white flowered geranium lacked oxidase, and it is believed that its albinism Is 

 due to this fact. 



The authors summarize their results concerning the nature of the oxidases in 

 flowers, stating that cells in which anthocyanin pigment is present contain oxi- 

 dase in one of two forms, a peroxidase or a complete oxidase. The latter is 

 found in the flowers of sweet william, geranium, and certain species of Pyrus 

 and Prunus. Peroxidase is of more general distribution and occurs in primula, 

 sweet pea, garden pea, and many other plants. The oxidase content of a plant 

 was found to vary with external conditions. Tissues which are normally illu- 

 minated contain less peroxidase than corresponding tissues of plants kept in 

 darkness. The organic peroxid constituent of the complete oxidase, though 

 absent from the normal plant, makes its appearance after that plant has been 

 kept for some time in complete darkness. Wound oxidases are said to resemble 

 those which are concerned in the work of pigment production. 



On the presence of diastase in certain red algae, E. T. Bartholomew (Abs. 

 in Science, n. ser., 37 (1913), No. 9^9, p. 382). — Various concentrations of ex- 

 ti'acts from a number of species of red algfe were used in testing cornstarch 

 paste, and the results showed that although starch digestion was slower in the 

 tubes treated with the algal extract than in those treated with commercial 

 diastase, yet in time the digestion was complete. This appears to demonstrate 

 the presence in the Floridese of a diastase similar to that in green plants. 



An optimum culture medium for a soil fungus, J. B. Pollock {Abs. in 

 Science, n. ser., 31 (1913), No. 9^9, pp. S86, 387).— In collaboration with Miss 

 Rose M. Taylor the author has carried on experiments to determine an optimum 

 culture medium of known composition and of simple constitution. The experi- 

 ments were conducted with Myceliophthora sulphurea, and 16 organic com- 

 pounds were tested as to their availability for carbon, and incidentally for 

 hydrogen and oxygen. Five compounds were tested for nitrogen supply, while 

 magnesium sulphate was used in all cultures to supply magnesium and sulphur, 

 and monopotassium phosphate to furnish phosphorus and potassium. The vari- 

 ous materials were used in different proportions. 



The medium in which the fungus was found to give the optimum results was 

 saccharose 2/5 M, calcium nitrate 1/250 M, monopotassium phosphate 1/10-1/100 

 M, and magnesium sulphate 1/1000 M. Saccharose, it is said, has a decided ad- 

 vantage over both dextrose and maltose in that it can be obtained in a purer 

 form, the ordinary rock candy to be obtained almost anywhere being more nearly 

 chemically pure than the grades of maltose and dextrose which are usually 

 designated as chemically pure. 



Studies in bacteriological analysis of Indian soils, I, 1910—11, C. M. 

 Hutchinson (Mem. Dept. Agr. India, Bad. Ser., 1 (1912), No. 1, pp. 65, pis. 



