386 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Poles, Preservative Treatment of. By William H. Kempfer 



{U.S.A. Dep. Agr., Forest Service, Bull 84; June 12, 1911).— Several 

 years ago the Forest Service undertook a number of experiments with 

 a view to prolonging the life of poles, and the result of these investiga- 

 tions, which are so far most successful, is given in the above paper. 



Some of the systems adopted have been successfully carried out in 

 this country for several years back. — A. D. W. 



Potato, After-ripeningr of the. By Charles O. Appleman 

 {Bot. Gaz. pp. 306-315, Oct. 1911). — The following table summarizes 

 the results obtained by the author : — 



Exposure in 

 days 



14 



28 

 42 



Temperature 

 in 0°O. 



r 20-25 

 1 0-1 

 / 20-25 

 1 0-1 

 / 20-25 

 0-1 



Glucose 

 Per cent. 



•37 

 •52 

 •32 



1^8 

 •3 



3-5 



Sucrose 

 Per cent. 



0- 55 



1- 3 



0- 54 



1- 65 



0- 84 



1- 8 



Starch 

 Per cent. 



14-4 

 13-2 

 14 

 11 

 13-6 

 9-6 



Diastase 

 (see below) 



30 

 25 

 30 

 20 

 25 

 20 



Catalase 

 (see below) 



40- 6 

 37-6 



41- 2 

 28-6 

 44 

 26-4 



Peroxi- 

 dase (see 

 below) 



35 

 35 

 33 

 32 

 32 

 25 



The unit in the diastase column was the number of c.c. potato 

 extract required to digest 100 c.c. starch solution in twenty- four hours 

 at 48^ 0. The catalase unit was the number of c.c. of O2 evolved in ' 

 three minutes. The unit in the peroxidase column was the number 

 of seconds required to reach standard colour. There is a long dis- 

 cussion as to the best methods of estimating peroxidase. j 



The rest period of potatos is shortened by a temperature of 0° G., 

 but there was no appreciable difference in the diastase activity at the I 

 end of six weeks, as the variety of potato used was then nearly at the 

 termination of its period of rest. 



The behaviour of catalase corresponds with that of respiration under 

 similar conditions. — G. F. S. E. 



Potato Scab. By W. J. Morse {Phytopathology, ii. pp. 146- 

 149 ; Aug. 1912 ; figs.). — The author concludes as a result of experiment 

 that the germs of the potato scab organism {Oospora scabies) are able to 

 pass through the digestive tract of the horse and cow, and pass into 

 the manure without injury, but more readily in the case of the former. 

 This manure is thus a source of infection wKen the animals are fed 

 with scabby potatos.— F. J. G. 



Potato, The Fusarium Blight or Dry Rot of the. By Thos. P. 



Manns {U.S.A. Exp. Stn. Ghio, Bull. 229, 1911).~The writer is j 

 emphatic on the point that all potato growers should know the early | 

 symptoms of the disease, so as to be able to recognize them in the 

 tubers before planting, and thus to a large extent prevent further 

 infection of the soil. The chief symptoms in the tuber range from 

 slight discoloration of the flesh at the stem end to darkening and 



