DISEASES OF PLANTS. 149 



Sphaeropsis tumefaciens n. sp., the cause of the lime and orange knot, 

 Florence Hedges (Phytopathologif, 1 {1911), No. 2, pp. 63-65, pi. i).— The 

 author describes a new species of fungus, 8. tumefaciens, which produces galls 

 from one-fourth to 3 inches in diameter on the branches of the lime {Citrus 

 hystrix acida) and of the orange. 



The young tumors are covered by the smooth, green bark, which later usually 

 splits, dies, and falls away, leaving the woody tissues exposed or covered with 

 a softer, more or less crumbly layer about the thickness of ordinary bark. If 

 the mycelium is present in abundance, its dark-colored hyphfe impart a black 

 appearance to the tissues of the knot. The fungus rarely fruits in laboratory 

 cultures, but pycuidia containing spores were finally obtained on a 3-months-old 

 corn-meal flask culture of the orange strain. Thus far no perithecia have been 

 observed, but pycnidia and siiermogonia occur in great numbers in artificial 

 infections on the host and in cultures of the vigorously fruiting strains from 

 the corn-meal cultures. 



A new disease of mulberries, F. Bubak {Ber. Deut. Bot. Gesell., 29 {1911), 

 No. 2, pp. tO-Ui, fltj. 1). — The author describes as new a fungus, DofhiorelUna 

 twrikoffii n. g. and sp., which is found on dead mulberry branches in the stro- 

 matic layers of Thyrostroma kosaroffli {Steganosporium siralcoffli). 



On Melanconis modonia, a parasite of the chestnut in Brittany, V. Ducomet 

 {Bui. Soc. Nat. Agr. France, 71 {1911), No. 1, pp. 99-102). — A description is 

 given of the symptoms of this disease, often known as black canker, as it occurs 

 in Brittany, where it is common in certain localities. 



It is claimed that the disease in this region attacks the tops and branches 

 first, and finally works its way downward toward the roots, causing many 

 branches to die and often ringing the trunk, thereby killing the entire tree. 

 The disease apparently begins in the 1-year-old terminal shoots, and is believed 

 to enter by way of the leu tides. 



The black canker of the chestnut, G. Briosi and R. Fabneti {Atti. R. Accad. 

 Lincei, Rend. CI. Sci. Fis., Mat. e Nat., 5. ser., 20 {1911), I, No. 4, PP- 201^ 

 207). — This is a controversial article on the taxonomic position of the fungus 

 Melanconis perniciosa, which is claimed by the authors to be the cause of the 

 chestnut canker, and contains critical observations on an article by Griffon 

 and Maublanc (E. S. R., 24, p. 652) in which they claim that M. perniciosa and 

 M. modonia are identical. The authors, after comparing the characters of the 

 2 fungi, hold that they are not identical. 



The parasitism of Diaporthe parasitica on the chestnut, E. Pantanelli 

 {Atti. R. Accad. Lincei, Rend. CI. Sci. Fis., Mat. e Nat., 5. ser., 20 {1911), I, 

 No. 5, pp. 366-372). — In addition to a general review of the history of this dis- 

 ease, the author discusses other varieties of Diaiwrthe on the chestnut, and the 

 characters, taxonomic position, germination of spores, and general life cycle of 

 this fungus. It is claimed that inoculation experiments have shown that the 

 fungus is capable of attacking Italian chestnuts, and rigid quarantine regu- 

 lations are therefore advised against all chestnut plants from the United States. 



The chestnut bark disease, F. W. Rane {Boston: State Forester, 1911, pp. 7, 

 j)Is. 2). — This is a popular discussion of this serious chestnut disease, in which 

 the author describes its growth and symptoms and methods of control and 

 eradication. It is stated that as yet there is no known method of curing the 

 disease or of saving a thoroughly infested woodland, but in regions where the 

 disease has just appeared the prompt destruction of infected trees at the outset 

 is advised. 



Hevea disease in Ceylon ( Phytophthora faberi), H. N. Ridley {Agr. Bui. 

 Straits and Fed. Malay States, 10 {1911), No. 3, pp. 70, 7i).— This fungus 

 attacks both cacao and Para rubber. 



