Notes and Brief Articles 



117 



the fungus had made considerable growth, transfers were made 

 from the agar slants to sliced sterile carrots in large Erlenmeyer 

 flasks, and the cultures incubated for 3 months at a temperature 

 of 32 0 C. The fungus makes comparatively slow growth both 

 on hard potato agar and on the carrots. While still in an actively 

 growing condition the fungous mats were removed from the 

 flasks, and, when thoroughly dry, were finely ground. The fol- 

 lowing enzymes were found to be present in the fungus : Esterase, 

 maltase, lactase, sucrase, rafrmase, diastase, inulase, cellulase, 

 hemicellulase, urease, rennet, and catalase. 



A handsome paper on the mosaic disease of cucurbits by S.. P. 

 Doolittle, has appeared as Bulletin 879 of the U. S. Department 

 of Agriculture. According to the author, this disease has appar- 

 ently been present in the United States for nearly 20 years, but 

 prior to 1914 its importance was practically unrecognized. It 

 appears both in the field and in the greenhouse in nearly all sec- 

 tions where cucurbits are of commercial importance. Nearly all 

 cultivated cucurbits are susceptible to it, but the cucumber crop 

 seems to be most seriously affected, particularly in the Central 

 States and the trucking regions of the South. The diseased 

 plants develop a yellow mottling of the younger leaves, accom- 

 panied by a wrinkled or savoyed appearance. The older leaves 

 gradually turn yellow and die, leaving the basal portion of the 

 stem bare. 



No visible causal orgainsm has been associated with cucurbit 

 mosaic, and the disease appears to be unrelated to soil conditions. 

 The juice of mosaic plants contains an infective principle, or 

 virus, however,which possesses certain definite properties. The 

 expressed juice of mosaic plants is rendered non-infectious if 

 heated above 70 0 C. The power of infection is also destroyed by 

 formaldehyde, phenol, and copper sulphate in 0.5 per cent solu- 

 tions and by mercuric chlorid in a strength of 1:2,000. A 10 

 per cent solution of chloroform will also render the virus inactive, 

 but neither 5 per cent chloroform nor 10 per cent toluene are 

 effective. 



The juice of mosaic diseased plants may be diluted to 1 : 10,000 



