194 SUMMARY OF CURRENT RESEARCHES RELATING TO 



fungus is given, and various notes as to the biology and the occurrence 

 of the different forms are added. 



The chestnut bark disease * has not been recorded in this country, 

 but an account of it is pubhshed by the Board of Agriculture, with 

 instructions as to the best methods of combating the disease, should it 

 appear. It attacks all species of Gastanea except the Japanese variety. 

 The fungus causing the disease is referred to Diaporthe parasitica. It 

 starts in wounds in the bark, and girdles the tree, the part above the 

 girdle dying off. 



Ed. Griffon and AH Riza f report on diseased maize received from 

 Cochin China. The axis the of head had a greyish appearance, the pericarp 

 of the grains more or less blackened, although the embryo and the 

 albumen were healthy. In other cases the embryo also was destroyed. 

 The cause of the disease was found to be a minute fungus belonging to 

 the Fungi Imperfecti, and diagnosed as Dothiorella Zese sp. n. The 

 effect of the fungus on the different tissues is described. 



J. Eriksson % has made a study of the violet-coloured Rhizoctonia 

 as it appears on beet, carrot, etc. He describes the disease thus : — 

 During the time of vegetation, the fungus forms under the soil a sterile 

 parasitic felted mycelium of a violet-red colour. In the "felt" arise 

 somewhat round dark ])rown sclerotia, resembling perithecia. This is 

 the Rhizoctonia condition of the fungus. Later it spreads upwards and 

 forms above the soil a membranous coating round the stem of a delicate 

 rose tint, from 5-15 mm. upwards, and also spreading occasionally over 

 the surface of the soil like a thin leaf. It is the Hypochnus stage, and 

 produces basidia and spores. Instructions are given as to treatment of 

 the disease. 



L. Petri § gives an account of recent research on the " inky " 

 disease of the chestnut. He had found Endotlda radicalis in the living 

 tissues of the cortex as well as other fungi on the branches, and he 

 proceeds to discuss the possil)le infection of the roots by some organism, 

 or the influence of some adverse condition in the soil. No definite 

 results were obtained. 



E. Pantanelli || also publishes a paper on the subject, mainly con- 

 cerned with the origin of the disease, as to whether the fungus is 

 indigenous or is imported from America. He found considerable mor- 

 phological differences, which sufficed to separate the European Endothia 

 radicalis from the American chestnut fungus, E. parasitica. The latter 

 form attacks the branches, while E. radicalis is a fungus of the roots 

 or the collar. 



F. W. l^egerlF has examined the tubercles formed on the Italian 

 cypress, and has found the mycelium and the fruiting bodies of apyreno- 

 mycetous fungus, Ceratostorna. It has been held by Cavara that these 

 tubercles are caused by bacteria, ])ut no trace of these organisms could 

 l)e found along with the fungus in tliis instance. 



* Journ. Board. Agric, xix. (1913) pp. 848-50. 

 t Bull. Soc. Mycol. France, xxviii. (1912; pp. 333^7 (2 pis.). 

 X Rev. Gen. Bot., xxv. (1913) pp. 14-30 (4 figs.). 

 § Atti Reale Accad. Lincei, cccix. (1912) pp. 863-9. 

 11 Atti Reale Accad. Lincei, cccix. (1912) pp. 869-75. 

 t Mycol. CentralbL, ii. (1913) pp. 129-35. 



