DISEASES OF PLANTS. 545 



insect, and other injuries and depredations. The principal causes of injury 

 are described at some length. In an appendix the following topics are treated: 

 The causes of injury to cultivated plants, fungicides, insecticides, treatment of 

 fungi and insects by combined applications, spraying apparatus, carbon bisul- 

 phid as an in.secticide, methods for combating wild mustard by spraying with 

 iron sulphate, seed treatment for combating grain smuts, American gooseberry 

 mildew, field mice, and inoculation of leguminous plants with root-tubercle 

 cultures. 



Mycological notes, E. Mayor (BhL Soc. Neuchdtcl. Sci. Nat., 36 (1909). pp. 

 30-36; abs. in Bot. VentbL, 111 {1909), No. 16, p. J,07).—Of the fungi noted the 

 following are of special interest: Ochropsora sorbi on Pyrus communis; an 

 jecidium on Sedum rcftexum near plants of Eceleria cristata and Valesiaca which 

 were infested with Puccinia longissima; an secidium on Crepia biennis near 

 plants of Carex muricata infested with a Puccinia ; and aecidia on Cirsium 

 rivulare near plants of Carex goodenoughii infested with Puccinia. Attention 

 is called to the outbreak of Oidium. quercinum on Quercus sessiliflora, Q, pedun- 

 ciilata, and Q. pubescens. An oidium was also found on Fagus sylvatica. In 

 this connection the author notes the finding in 1899 of an oak oidium associated 

 with the i)erithecia of a Microsphjera. 



Researches on the life history of parasitic fungi, C. K. Bancroft (Ann. 

 Bot. [Londmi], 2-'t (1910), No. 9 J,, pp. 339-372, pi. 1).—A study has been made 

 of Cladosporium herbarum and a disease caused by Hormodendron to determine 

 the possible relationship existing between these two fungi. 



After describing the disease due to Hormodendron and presenting evidence 

 regarding its parasitic nature, the author gives an account of the relationship 

 between the two fungi. He believes that the life cycle is composed of two 

 conidial forms, Hormodendron and Cladosporium. The Hormodendron form 

 is a summer parasitic form, which in the summer produces a disease on the 

 green leaves of a number of species of plants. When the leaves die it passes 

 into the Cladosporium stage. 



The Cladosporium is a late form and exists as a saprophyte on dead leaves 

 that have been previously attacked by Hormodendron. It gives rise to Hormo- 

 dendron if the temperature is moderately high, but at lower temperatures it 

 reproduces itself. In the winter Cladosporium exists in the form of micros- 

 clerotia, and on the return of spring these germinate, producing conidia of 

 Cladosporium. The Cladosporium conidia, after germinating, give rise to 

 conidia of Hormodendron, which serve to continue the disease during the 

 summer. 



A list is given of various species of fungi which are regarded as synonymous 

 with C. herbarum. 



A new European species of Peronospora, G. W. Wilson (Ann. MyeoJ., 8 

 (1910), No. 2. pp. 185-187). — After a brief discussion of the species of Peronos- 

 pora found on leguminous hosts, the author describes P. ononidis n. sp. on the 

 leaves of Ononis rcpcns and O. spinosa from Germany. 



Fusarium nivale, the cause of white mold and its connection with Nectria 

 graminicola, G. Ihssen (Centbl. Bakt. [etCi, 2. Abt., 27 (1910), No. 1-3, pp. 

 1,8-66, pi. 1, figs. 8). — ^The author claims to have proved the identity of F. 

 nivale and N. graminicola by breeding and infection experiments in which 

 (1) Fusarium diseased oat plants were placed under bell jars and the resulting 

 fructification proved to be the perithecia of .Y. graminicola, (2) healthy plants 

 were infected with either the Fusarium mycelium or conidia and the resulting 

 perithecia identifiefl, and (3) A', graminicola perithecia were grown from pure 

 cultures of Fusarium mycelia. 



