158 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(TtL. Petri * has already stated that he has reason to heheve that the 

 ■" ink-disease " of chestnuts is not due to the attack of a Gori/nmm, tliat 

 fun2:us found on the tissues being a saprophyte. He now pubhshes a 

 further account of his observations, cultural and microscopic, which 

 tend to confirm his view that the disease is caused by some one of the 

 Polyporei. He has found mycelium in the tissues that he was able to 

 identify with a species of Foria and with Fomes Ribis. 



D. Hegyi t reports a severe attack on clover {Trifolium fratmse') by 

 the fungal parasite GJc^osiporium cauUvorum. The plants were ])lackened 

 and then entirely destroyed. The fungus spores are disseminated along 

 with the clover seed, and as a remedy the author recommends soaking it 

 in copper sulphate. 



B. A. Bailey % has recorded an instance of diseased seedling goose- 

 berry plants being cured from disease by transplanting them to new 

 ground, thus confirming Salmon's view that the perithecia fall to the 

 ground and reinfect the trees in spring. Any perithecia that remain on 

 the trees are not viable, unless under special conditions of tempera- 

 ture, etc. 



P. BijI § has described a " wilt " or "crown-rot" disease of carna- 

 tions which is caused by a species of Fusarium. The rot is evident on 

 the stem just below the soil level, and soon causes the death of the whole 

 plant. The disease is especially virulent in South Africa. The author 

 gives an account of his infection experiments and of the behaviour of 

 the fungus on different culture media. 



The same author |1 has made a study of the " dry-rot " disease of 

 maize, Diplodia Zese, otherwise known as mildew or mould. Special 

 attention was given to the effect of diseased maize on stock, and it was 

 ascertained that though it appeared to be non-poisonous, yet, judging 

 from chemical substances produced by tlie fungus in artificial media, the 

 mildewed maize could not be considered a healthy article of food. The 

 spores were found to have little resisting power, and they lose viability 

 soon after passing through the alimentary tract of animals. The fungus 

 was easily cultivated on manure and on other artificial media. The 

 destruction of infected maize is recommended, 



A serious disease of snap beans was found by J. A. McClintock If to 

 be caused by Sderotlnia, which he had reason to believe was a special 

 strain of S. libertUwa. Cross-inoculations proved that the disease was 

 reproduced on lettuce. Experiments on growth conditions showed the 

 advantage to the fungus of a moist atmosphere ; it took twice as long to 

 produce decay when the air was dry. 



* Atti Reale Accad. Lincei, occxiii. (1916) pp. 172-6 (2 figs.). 



t Mfezogorz. Szemle, xxxiii. 2 (Budapest, 1915) p. 53-8. See also Bot. Centralbl., 

 cxxxii. (1916) p. 69. 



X Ann. Appl. Biol., ii. (1915) pp. 162-5. See also Bot. Centralbl., cxxxii. (1916) 

 p. 121. 



§ Ann. Appl. Biol., ii. (1916) pp. 267-90 (4 pis.). 



II Dept. Agric. Union S. Africa, Sci. Bull., xii. (1916) p. 5-59 (15 pis.). See also 

 Bot. Centralbl., cxxxii. (1916) p. 240. 



t Phytopathology, vi. (1916) pp. 436-41 (2 figs.). 



