136 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



action of an enzyme liberating hydrocyanic acid. The leaves also contain 

 a large proportion of the hydrocyanic acid in the free state. 



The leaves of Phaseolus lunatus contain the glucoside phaseo- 

 lunatine (C 10 H 17 O 6 N).— S. E. W. 



Podoearpus, Staminate Cone and Male Gametophyte of. 



By L. Lancelot Burlingame (Bot. Gaz., xlvi., September 1908, pp. 161- 

 178). — There.are two primary prothallial cells, which may form as many 

 as eight prothallial cells ; also both stalk and body cells, and 12 to 24 

 chromosomes. — G. F. S.-E. 



Polypodium Pteropus, Bl. By A. Ernst {Ann. Jard. Bot. Buit., 

 vol. vii., pp. 103-143; 3 plates). — The influence of environment on the 

 structure and growth of Polypodium Pteropus (which was found growing 

 submerged at the bottom of a temple tank at Lanbok, in the garden of the 

 former Sultan of Lingsar), is described. — S. E. W. 



Potash, Experiments with Feldspathic Rock as a Source of. 



By B. L. Hartwell and F. B. Pember (U.S.A. Exp. Stn. Bhode I., Bull. 

 129 ; June 1908).— The results of water culture experiments with wheat 

 seedlings in which ground feldspathic rock (of a fineness that it would pass 

 a sieve with 200 meshes to the linear inch) took the place of potassium 

 chloride in some of the bottles. Other experiments were performed in 

 pots. In neither case did the finely ground rock appear to provide an 

 amount of potash sufficient to justify the investigators in recommending its 

 use as fertilizer even upon an experimental scale. — F. J. C. 



Potato, Brown Spots in Tuber. By W. J. Morse ( U.S.A. Exp. Stn. 

 Maine, Bept. 1907, pp. 318-319 ; figs.). — Brown spots in the flesh of the 

 potato are described. They were not apparently due to the presence of any 

 fungi or bacteria. Some varieties appear to be more susceptible than others 

 and the disease is looked upon as constitutional. — F. J. C. 



Potato Diseases in San Joaquin County, California. By 



W. A. Orton (U.S.A. Dep. Agr. Giro. 23 ; January, 1909).— The principal 

 cause of the marked decrease in the yield of old potato land is the 

 presence of a fungus disease, the wilt or dry rot (Fusarium oxysporum, 

 Schlr.). The leaves assume a dull unhealthy appearance, with a rolling or 

 curling of the margins. Gradually the tops wither or fall over; the 

 diseased plants are easily pulled up, the roots partly dead and brittle. 

 The fungus appears on them as a white or pink mould. When the 

 underground portion of the stem is cut across, a pronounced brown 

 discoloration is visible. The brown stain is also found in the branches 

 K il ling to the tubers. When the potatos are dug there is rarely any 

 external evidence of disease. When infected potatos are stored in a 

 warm temperature, dry rot soon appears. — M. C. C. 



Potato Experiments. (Jour. Dep. Agr. Vict. Sep. 1908, pp. 559- 

 575). r— Immature potato seed in the case of * Beauty of Hebron ' gave better 

 results than were obtained from seed perfectly ripe and well matured. 

 Chan- ! from one district of the State to another did not, however, 



appear to affect the productiveness.— C. H. H. 



