ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 207 



the enzyme pectosinas§, and probably precipitating the pectin of the 

 lamella as calcinm pectate. This latter is strongly hydrophyllic, and 

 maintains the firmness of the frnit even after rotting, and, as it is an 

 imbibing " gel," it aids the fnngus in providing water supply. A. L. S. 



North American Species of Discina. — F. J. Seaver {Mycolo(jia, 

 1921, 13, (i7-71, 1 pi.). The genus is distinguished from othev Fezizx 

 by the wide-spread apothecia and the apiculate spores. The writer 

 describes four species that have been found in the United States, all of 

 them also European ; they grow on the ground, mostly in woods. 



A. L. S. 



New DimorphomyceteaB. — Roland Thaxter {Froc. Amer. Acad. 

 Arts and Sci., 1920, 55, 211-82). This section of Laboulbeniales 

 includes those unisexual forms in which the male individual possesses one 

 or more compound antheridia ; there are four genera, Dimorphomyces, 

 Dimeromyces, Streblomyces, and Poly and romyces, the last a new genus, 

 with one species and one variety. The author describes the peculiar 

 sexual organs of this group. A great many new species are also described. 



A. L. S. 



Relation of the Health of the Host and other Factors to Infec- 

 tion of Apium graveoleus by Septoria Apii. — H. E. Thomas {Bull. 

 Torre.y Bot. Club, 1921, 48, 1-29). The writer discusses the relation 

 between the condition of the host and parasite, gives a historical 

 account of the fungus in question, and describes his methods of tackling 

 the problem — by culture experiments, effect of fertilizers, etc. He has 

 shown by his experiments that Septoria Apii, though it readily assumes 

 the saprophytic habit, has become so adapted to its host that it increases 

 as the host becomes stronger and better nourished, and he found also 

 that infestation of the host-roots by Nematodes inhibits the growth of 

 the fungus. Citations are made from workers on other fungi who came 

 to similar conclusions. A. L. S. 



New Species of Phomopsis Parasitic on the Douglas Fir. — 

 Malcolm Wilson {Trans, and Froc. Bot. Soc. Edin., 1920, 28, 47-9). 

 Wilson gives here a diagnosis of the new species Fhomopsis Fseudo- 

 tsugse. It attacks the Douglas fir in two ways — either the leading shoot 

 is killed back for some distance, or the young tree is attacked a short 

 distance above the ground level. The pycnidia grow on bark or on the 

 leaves. They produce three types of spore, or rather spores in three 

 different stages of development occur in different pycnidia. A. L. S. 



New Species of Uredinese. XIII.— J. C. Arthur {Bull. Torrey 

 Bot. Club, 1921, 48, 31-42). The writer publishes a number of new 

 species ; he adds also a number of name combioations. He revises the 

 names of three of his previous genera : Lysospora (a synonym of 

 Tranzschelia, and now replaced by Lipospora), Telospora (which becomes 

 Teleutospora), and Dasyspora (which becomes a synonym of Micro- 

 •puccinia Rostr.). Arthur gives the history of these genera, and the 

 reasons for alteration. A. L. S. 



