98 MORPHOLOGY AND TAXONOMY, FUNGI, ETC. [BoT. Absts., Vol. X, 



wintering, besides its usual pycnidia, numbers of perithecia. Pure cultures, made with the 

 ascospores, proved the relationship between the pycnidia and perithecia; infection experi- 

 ments with ascospores provided additional proof. Apparently the conidial form resembles 

 very closely Hollos' Diplodina lycopersici, if it is not actually identical with it. The perithecia 

 may belong to Mycosphaerella or Didymella. Owing to the presence of paraphyses, Klebahn 

 places the fungus in the genus Didymella, though thus far this genus has not included patho- 

 genic species. Provisionally the ascigerous form may be known as Didymella lycopersici n. 

 sp. The author concludes his treatise with a review of related Ascomycetes. But, in view 

 of the fact that most of these apparently related fungi have not been successfully studied as 

 to structure and development, a regrouping of them does not, in his opinion, seem possible at 

 present. — H. T. Giissow. 



622. Laibach, F. Untersuchungen iiber einige Septoria-Arten und ihre Fahigkeit zur 

 Bildung hoherer Fruchtformen. I und II. [Septoria species in relation to higher fruiting 

 forms.] Zeitschr. Pflanzenkrankh. 30: 201-223. 12 fig. 1920. — Several species of the genus 

 Septoria Fries are chosen as subjects for research concerning the production of ascigerous 

 forms. The relationship of S. sorbi to a species of Mycosphaerella, discovered on overwintering 

 leaves of Sorbus aucuparia, is proved through infection experiments and pure cultures. In 

 determining the Mycosphaerella the author finds it necessary to discuss the Septoria species 

 occurring on Sorbus. He decides that Septoria sorbi, S. hyalospora, and S. piricola are 3 

 very closely related fungi which possess almost identical ascigerous forms. He prefers to 

 regard them as distinct, and considers the ascigerous form of S. piricola Desm. as Mycosphae- 

 rella sentina (Fuck.) Schroeter on pear leaves, of Septoria sorbi Lasch as Mycosphaerella aucu- 

 pariae Lasch on Sorbus aucuparia, and of Septoria hyalospora (Mont, et Ces.) Sacc. as My- 

 cosphaerella topographica (Sacc. et Speg.) Lindau on Sorbus torminalis. Septoria scabiosicola 

 (DC.) Desm. was also studied but an ascigerous form was not found. — H. T. Giissow. 



623. Peyronel, Beniamino. La forma ascofora dell 'Oidio della quercia a Roma. [The 

 ascigerous stage of the Oidium on oak at Rome.] Staz. Sper. Agrarie Ital. 54: 5-10. 1921. — 

 The author in November and in December found the perithecia of the Oidium on oak leaves in 

 2 different localities in Rome. He attributes their development to the joint action of cold 

 weather and low humidity, and to the necessity of better adaptation of the organism to these 

 conditions. After a review of various related species, the conclusion is reached that the 

 name of the organism is Oidium gemmiparum (Ferraris) nob. (Oidium quercinum var. gemmi- 

 parum Ferr. in Ann. Mycol. 1909; 0. alphitoides Griffon et Maublanc in Bull. Soc. Mycol. 

 France, 1910). — A. Bonazzi. 



624. Rossi, Gino de. I lieviti apiculati nella fermentazione vinaria. [The yeasts of the 

 group apiculatus and their role in the fermentation of wine.] Staz. Sper. Agrarie Ital. 53: 

 233-297. Photomicr. 1-3, fig. 1-8. 1920. — A contribution is presented on the phj^siology, 

 morphology, and classification of this comprehensive group of organisms. The paper is di- 

 vided into 5 chapters as follows: (1) Synthetic review of the collective species <Sacc/iar-omyces 

 apiculatus; (2) description of 2 new species of Pseudosaccharomyces common on the grapes 

 and in the musts of the region; (3) studies upon the influence of these organisms upon the path 

 of the fermentation caused by Saccharomyces ellipsoideus; (4) experiments upon the use of 

 Pseudosaccharomyces magnus in wine manufacture; (5) conclusions. An extensive list of the 

 literature bearing on the subject is appended. Fifty-five stock cultures isolated and studied 

 are divided into the 2 following groups, which have the general characteristics indicated: 

 (1) Pseudosaccharomyces apictdatus, a bottom yeast; cells single or in groups of two, 3.4-6 X 

 1.5-3.2 IX, gram positive, containing glycogen and fat, non-spore forming, gelatin liquefying, 

 limits of growth between 1-3.5 and31-35.5°C., thermal death point at44^7°C. The organism 

 ferments glucose and levulose, producing only 3.15-4.55 per cent alcohol, while it fails to ferment 

 maltose, lactose, and saccharose. (2) Pseudosaccharomyces magnus, a bottom yeast; cells 

 grouped in chains of 3-4, each cell measuring 4.8-9.6 X 2.7-4.8 m- While the organism behaves 

 somewhat similar to P. apictdatus, it does not liquefy gelatin and has a maximum growing 

 temperature of 33-35 C. and a thermal death point of 49-50°C., and under the same conditions 



