40 THE CURLY-TOP OF BEETS. 



32. Woods. A. F. Botanical Gazette, September, 1S97, and Centralblatt fiir 



Bakteriologie, Parasitenkunde, und Infektionskrankheiten, vol. '■'>, pt. 2. 

 Studies on the carnation disease known as " stigmonose " are described. 

 Tbe author was unable to produce witb bacteria tbe same results as tbose 

 described by Arthur and Bolley. 



33. Woods, A. F. On tbe relation of oxidizing enzymes to the destruction of 



chlorophyll. Centralblatt fiir Bakteriologie, Parasitenkunde, und Infek- 

 tionskrankheiten, vol. 5, pt. 2. 1899. 



The destruction of chloroplasts may probably be explained by increased 

 oxidation taking place in the cells. 



34. Observations on the mosaic disease of tobacco. Bulletin 18, Bureau 



of Plant Industry, U. S. Dept. of Agriculture. 1902. 



Woods describes the mosaic disease of tobacco and shows it to be 

 probable that there is a disturbance of nutrition due to a lack of balance 

 in the relative amounts or activity of enzymes, that the oxidizing enzymes 

 seem to be abnormally active in the diseased cells, and that the mode of 

 operation is to weaken or retard the action of the diastase. The action 

 of the oxidizing enzymes upon the diastase, therefore, retards the pro- 

 duction of sugar, and consequently of proteids and reserve nitrogen in 

 general. The conclusion is reached that the disease can not be due to 

 parasites, but must be attributed to a disturbance of the normal physio- 

 logical activity of the cells in question. Whatever causes the reduction 

 of available nitrogenous reserve food, especially soluble nitrogen, below 

 the requirements of dividing cells may cause this disease in the tissues 

 of certain plants. 



35. Stigmonose, a disease of carnations and other pinks. Bulletin 19, 



Division of Vegetable Physiology and Pathology, U. S. Dept. of Agri- 

 culture. 1900. 



The disease is described and its cause attributed to aphides, red spiders, 

 thiips, and other sucking insects. It was reproduced under test con- 

 ditions with these insects. The effects of the insect punctures on the plant 

 cells are described. 

 36. Science, n. s., vol. 11, no. 2G2, pp. 17-19. 



Important structural differences between the cells of the green areas 

 of mosaic plants and those of the light areas are pointed out. 



37. Carnations in health and disease. Florists 1 Exchange, vol. 13, 1901, 



pp. 1SS-1S9, and American Florist, vol. 10, no. 004, 1901. pp. 990. 



This paper contains substantially the matter presented in " Stigmonose, 

 a Disease of Carnations and Other Pinks." 



181 



