226 SUMMAH\ OF CURRENT RESEARCHES RELATING TO 



pine {Finus divaricata). The greatest damage is done by Peridermium 

 cerebrum, which causes gall-like excrescences on the trunks and branches. 

 Young trees are often covered with swellings which are very injurious 

 to their growth. The oak tree is the alternate host, and a due w'atch 

 must be kept in the forests for both stages of the fungus. Older trees 

 are attacked by Trametes Pini and by Polyporus Schiveinitzii. Fomes 

 annosus and Armillaria mellea occur rarely ; Lophodermium pinastri 

 occasionally attacks the leaves. 



Alf. Lendner * has given an account of a disease of the vine due to 

 a Hypochnus sp. n. It was localized round stem nodules caused 

 originally by frost, and forms a white felt. The author did not find 

 that it was the cause of very serious damage. 



Esther Young f has published a report on species of a Cercospora 

 parasitic on plants in Porto Rico. It is a leaf genus of fungi. Six 

 new species are added to those already known. 



\V. B. Mercer:}: writes on an outbreak of mildew that attacked 

 greenhouse carnations in the Tyne Valley, and threatened to become 

 serious, but was held in check by repeated sprayings. The disease is 

 characterized by the appearance on the leaves of patches of white mould, 

 which gradually spread and assume a yellowish hue. Though living on 

 the outside of the plant this species of Oidium was found to bore its 

 way through the cuticle by means of the haustorium. Inside the 

 epidermal cell it becomes distended into a sacculate ending ; several 

 such haustoria were frequently found in one cell. The perithecium of 

 the fungus has not been observed. Directions are given as to the 

 means of combating the disease by different spraying solutions. 



A general review § of Plant Diseases in England and Wales for 

 1914-15 has been issued instead of the annual reports of the Horticulture 

 Branch of the Board of Agriculture. The report deals especially with 

 American Gooseberry Mildew, Warts, Disease of Potatoes and Corky 

 scab of Potatoes. Accounts are given of the prevalence of these 

 diseases during the period, and of the means taken to check the ravages 

 of the fungi by which they are caused. In all cases the diseases were 

 well under control. 



Lichens. 



(By A. LoRBAiN Smith, F.L.S.) 



Teloschistes in N. America. |1 — R. Heber Howe gives a detailed 

 account of the three species of this genus that occur m N. America. 

 The two first, T. flavicans and T. chrosphthalmus, are also British. The 

 former he ranks as maritime, the latter has a much wider distribution. 

 T. villosus, of which the tj^t specimen came from Peru, occurs in 

 Lower California. 



* Inst. Bot. Univ. Geneve, s6r. 9, i. (1915) pp. 26-8 (1 fig.). 



t Mycologia, viii. (1916) pp. 42-6. 



% Journ. Roy. Hort. Soc, xli. (1915) pp. 227-9 (figs.). 



§ Journ. Board Agric, xxii. (1916) pp. 931-7. 



II Bull. Torrey Bot. Club, xlii. (1915) pp 579-83 (2 figs.). 



