NOTES AND ABSTRACTS. 



527 



Experiments with the " pink rot " organism (Phytophthora erylhroseptica) 

 confirmed its role as a will-producing fungus, and tests of varieties of potato from 

 Holland and the United States showed that none of these were really resistant 

 to the attack of Spongospora subterranea. 



Successful attempts were made to repeat Rolf's work with Rhizoctonia Solani, 

 which is common in England, forming blackish sclerotia on the surface of potato 

 tubers. He considered this fungus a stage in the history of Hypochnus Solani 

 (giving it the name of Corticium vagum var. Solani), and now other workers have 

 confirmed this. 



Notes are also given on the diseases of the tubers induced by Spondylocladium 

 atrovirens and Spicaria Solani (the conidial form of Nectria Solani) and upon 

 the ordinary potato scab, which is shown to be preventible by soil sterilization, 

 and which American investigation has proved to be identical with the American 

 scab induced by Actinomyces chromogenus. — F. J. C. 



Potato, Late Blight of. By G. P. Darnell-Smith and E. Mackinnon {Agr. 

 Gaz. N.S.W. vol. xxvi. pp. 673-678 ; 3 figs.). — Irish Blight or Late Blight of 

 the potato is caused by the fungus Phytophthora infestans. To control this 

 disease avoid the use of seed from a crop that is known to have been diseased. 

 All haulms and small potatos from a diseased crop must be collected and burned. 

 Spray early and often with Bordeaux or Burgundy mixture. Some varieties 

 are less subject to attack than others, so that it is possible that a disease-resisting 

 strain may be produced. — 5. E. W. 



Potato-Scab Organism, Effect of Temperature on Germination and Growth 



of. By M. Shapovalov (Jour. Agr. Res. iv. pp. 129-134, May 1915; figs.\. — 

 The organism hitherto generally known as Oospora scabies has recently been 

 identified with Actinomyces chromogenus. The author has tested the temperature 

 relations of this organism and finds it germinates best between 35 0 and 40 0 C, 

 but these temperatures are unfavourable for long-continued growth. The 

 optimum temperature for growth is about 25 0 to 30 0 , the maximum being 40*5° 

 and the minimum, 5 0 C. Differences in temperature apparently also affect the 

 metabolism of the organism, for culture media were deeply stained when organisms 

 were growing below 3o°C, and but faintly or not at all at above 35 0 C. — F.J. C. 



Potato Storing. By L. Malpeaux (Jour. Soc. Nat. Hort. Fr. Nov. 1913, p. 

 747). — The writer examines the usual methods of storing potatos and advises 

 the complete removal of the eyes with a knife before storing, or, if a large crop 

 has to be treated, the tubers may be soaked in a 1 to 2 per cent, solution 

 of sulphuric acid in water. They may be dried and stored afterwards, and it 

 will not be necessary to wash them before feeding them to stock. It has been 

 proved that potatos will keep well in a silo of maize or some green crop, the 

 temperature of which must not exceed 72 degrees. M. Vilmorin has adopted 

 a method of storage which the writer describes. The tubers are put into cheap 

 wicker baskets holding about a hectolitre each, and the baskets are piled in double 

 rows. The piles take up practically no more room than an ordinary heap, cost 

 very little more, ventilation is assured, and if the storage place is dry the result 

 will be found most satisfactory. — M. L. H. 



Prairie Grove, Invasion of a (Bot. Gaz. lx. p. 331). — A grove was started 

 about forty years ago by planting seeds of species of Ash, Walnut, Elm, and 

 Maple. No cultivation was attempted. With regard to the undergrowth, it is 

 found that not only is the prairie sod now gone, but nearly every one of the original 

 prairie species has entirely disappeared, being replaced by some ninety invading 

 species, of which 85 per cent, are mesophytic and 60 per cent, are distinctly 

 woodland ; so that the area has been transformed from prairie to forest in 

 forty years. — G. H. 



Prickly Pears (continued). By J. H. Maiden (Agr. Gaz. N.S.W. vol. xxvi. 

 pp. 489-493; 1 plate, 1 col. plate). — The Scone Prickly Pear grows 10 feet 

 high and has very large joints (1 foot), with abundant white recurved spines in 

 clusters. The flowers are orange-yellow, and the barrel-shaped fruit has a rich 

 orange colour. It is perhaps identical with Opuntia Amyclaea. — S. E. W. 



Primula acaulis, Inheritance of Heterostylism in. By R. P. Gregory (Jour. Gen. 

 iv. pp. 303-4 ; Apr. 1915)- — Experiments show that the inheritance of long styles 

 is dominant over that of short styles in the primrose, as in Primula sinensis. 



F. J. C. 



Primula Myabeana (Bot. Mag. tab. 8603). — Formosa. Family Primulaceae. 

 Tribe Primuleae. Herb. Leaves 8 in. long. Scape single, 2 ft. long, with 6-10- 

 fiowered superposed whorls. Corolla purple, 1 in. across. — G. H % 



