338 SUMMARY OF CURRENT RESEARCHES RELATING TO 



; can live saprophytically on the dead leaves and can resist a long period 

 of drying. He recommends pulling and destroying the diseased 

 leaves. 



E. Saritz * notes the occurrence of Septoria Spergulariw sp. n. on 

 .Spergularia rubra in the neighbourhood of Dessau. 



Sterigmatocystis pseudonigra.f — Constantin and Lucet have en- 

 deavoured by culture and examination to determine the autonomy of 

 this species. They find that the microscopic characters exactly resemble 

 those of S. nigra ; but there are slight differences in culture appearance 

 which are constant for the two fungi. The writers are inclined to think 

 that the distinctions merit specific rank. 



Nutrition of Sterigmatocystis niger.f — Henri Coupin has tested 

 the growth of this fungus in Raulin's solution, eliminating one and 

 another of the elements composing it. Raulin had found that sulphate 

 of zinc was advantageous to fungus grow T th. H. Coupin, w T ith improved 

 methods, concludes that the favourable result was due to the antiseptic 

 nature of zinc, and that in properly sterilised solutions zinc is rather 

 hurtful than otherwise. Iron and silicon are also of no use to the 

 fungus. In a solution deprived of tartaric acid, Raulin failed to get 

 any growth as the culture was so quickly invaded by bacteria ; with 

 proper sterilisation, growth of Sterigmatocystis can be obtained in a 

 solution at first slightly alkaline. It is slow at first, but the mycelium 

 gradually provides its own acidity, and development then proceeds 

 rapidly. 



St. John's Disease of Peas.S — This disease is so named because it 

 makes its appearance about the period of St. John's day, towards the 

 end of June. C. van Hall finds that it is a root trouble and caused by 

 the fungus Fusarium vasinfectum, of which this is a new variety. The 

 plants turn yellow and die off, the roots having been invaded by the 

 mycelium of the fungus, the development of which is similar to that 

 causing the disease of cotton, watermelon, and cowpea in America. 

 Culture and infection experiments leave no doubt as to the accuracy of 

 the author's diagnosis. In some districts in Holland the culture of peas 

 has had to be given up, owing to this disease. 



Some plants of Sesamum orientale || from Turkestan were found by 

 A. von Jaczewski to be attacked by a Fusarium, the development of 

 which was identical with that of F. vasinfectum, and which has occurred 

 on a great variety of plants. Its absolute identity with the disease of 

 cotton cannot be assured until the perithecial stage Neocosmospora has 

 been found. The writer gives figures of mycelium and spores. 



Polydesmus exitiosus and Alternaria Brassicse.^f — Pietro Yoglino 

 has compared these two fungi by examining both and cultivating both 

 on the same host, namely cauliflower. The only difference noted between 



* Hedw. Beibl., xlii. (1903) p. 32. 

 t Bull. Soc. Myc, xix. (1903) pp. 33-44. 

 % Comptes Kendus, cxxxvi. (1903) pp. 392-4. 

 § Ber. Deutsch. Bot. Ges., xxi. (1903) pp. 2-5 (1 pi.). 

 ||| Ann. Myc, i. (1903) pp. 31-2. 

 ,^f Malpigliia. xvi. (1902) pp. 333-40 (1 pi.). 



