March 3, 1916] 



SCIENCE 



327 



pare illustrations which are scientifically accurate. 

 The cameras attend to the facts of form and Mr. 

 L. C. C. Krieger, who has had varied experience 

 and training in plant illustrating, attends to the 

 remainder of the work about as successfully. 



Relation of Catalase and Oxidase to Eespiratioti i>i- 

 Potato Tubers: Chas. 0. Appleman. 

 Bespiration in potato tubers is not only greatly 

 accelerated by various artificial treatments, but is 

 subject to fluctuations under natural conditions, 

 such as greening and sprouting. The rate of res- 

 piration varies in different parts of the same tuber 

 and tubers of different varieties. The modifica- 

 tion of the intensity of respiration in tubers under 

 such conditions was determined and at the same 

 time measurements were made of both the oxidase 

 and catalase activity in the juice. The data seem 

 to justify the following conclusions: (1) The oxi- 

 dase content in potato juice gives no indication of 

 the intensity of respiration in the tubers. In 

 other words, there is no correlation between oxi- 

 dase activity and the rate of respiration in these 

 organs. The author does not disclaim any role of 

 the demonstrable oxidases in respiration, but they 

 certainly are not the controlling factor in regulat- 

 ing the rate of respiration in potato tubers. (2) 

 Catalase activity in the potato juice shows a very 

 striking correlation with respiratory activity in 

 the tubers. 



Lipolytic Action in Germinating Teliospores of 

 Gymnosporangium juniperi-virginianae: G. H. 

 Coons. 



Teliospores from mature telial horns of Gymno- 

 sporangium juniperi-virginianae, were ground with 

 fine sand and a small amount of water extract ob- 

 tained. This extract when mixed with some neu- 

 tral fat (olive oil, castor oil) colored violet by lit- 

 mus, caused no change in color even after stand- 

 ing over night. When columns in which the spores 

 were germinated were similarly ground and an 

 extract of approximately the same amount ob- 

 tained, this was found to produce acid from neu- 

 tral fats. Reddening of the litmus which could 

 readily be detected by comparison took place in 

 two to four hours. In these experiments chloro- 

 form was used as an antiseptic. The experiments 

 were repeated vpith changes in the technique. 

 Telial horns were cut from several large galls. 

 These were divided into three portions. One por- 

 tion was left dry, the second was placed in water 

 at approximately 80° O. to kill the teliospores, 

 while the third was soaked in tepid water until the 



jelly-like telial columns were swollen. The water 

 in which the third portion was soaked was then 

 poured over the heated sori. This was an attempt 

 to balance the bacterial and fungal flora of these 

 two portions. The second and third portions were 

 then drained and kept under similar moist condi- 

 tions until the next morning. The columns were 

 then ground with a small amount of water and a 

 few cubic centimeters of water extract obtained. 

 Tests were made with neutral fats colored violet 

 with litmus. The third portion was the only one 

 to give an extract which had the power to pro- 

 duce acid from the fats. In these tests small test 

 tubes kept in the incubator at 37J° C. were used. 

 Potassium cyanide was used as an antiseptic. 

 When the active extract was boiled for a few 

 moments it gave a negative result in acid produc- 

 tion. The amounts of extract obtained were so 

 small that no attempt was made to precipitate with 

 alcohol. When oil which had been acted upon by 

 the extract from the germinated teliospores was 

 tested, glycerin was found to be present. None 

 was found in the oil untreated. The conclusion 

 seems justifled that in germinating teliospores, 

 lipase is present. This places the rust fungi in 

 the long list of organisms now known to possess 

 lipase. Attention may be called to the role of 

 lipase in germination. The rust spores are espe- 

 cially rich in oils and in the short period required 

 for germination one or more basidia, larger than 

 the spore itself, are sent out. In addition two or 

 more spores are formed on the basidium. The con- 

 version of the globules of oil into soluble products 

 easy of transport, seems to be a factor in this rapid 

 germination process. 

 The Action Upon Soil Nitrogen of Certain Crops: 



K. F. Kellerman and B. C. Weight. 



Twelve representative field crops were grown 

 alone and in certain combinations in large gal- 

 vanized iron buckets holding 100 pounds of soil. 

 When two species of plants were grown in associa- 

 tion, one half the number of plants of each species 

 was used as when each was grown separately. 

 Crops were all grown to maturity and harvested 

 close to the surface of the soil. With the growth 

 of millet, corn, Kafir corn and oats, practically all 

 the total nitrogen removed from the soil was re- 

 covered in the crop. With wheat, barley, rye and 

 sugar beets, all the nitrogen removed from the 

 soil was not recovered in the crop. Also when 

 hairy vetchj red clover and field peas were grown 

 there was a distinct loss of nitrogen. With the 

 growth of soy beans alone of the legumes, there 



