514 
87 870—37 885 Petersen—Petri. 
70 Petersen Henning Eiler. An account of Danish Freshwater-Phycomycetes, 
with biological and systematical remarks (Annal. Mycol., VIII, 1910, 
p. 494—560) fig. 
71 Petersen Otto Georg. Forst botanik. Paa Grundlag af Forelaesninger ved 
den kgl. Veterinaer og Landbohojskole. Kjobenhavn 1908, 442 pp., 
230 fig. 
72 Petersen Severin. Danske Agaricaceer. Systematisk Fremstilling af de 
hidtil i Danmark iagttagne Bladsvampe. Kopenhagen (G. E. C. Gad) 1907 
1. Heft, 208 pp. 
73 Pethybridge George H. Spongospora scab of potatoes (Irish Naturalist, 
XVIII, 1909, p. 118—119). 
74 — American gooseberry mildew in Ireland (Irish Gardening, II, 1907, No. 14, 
p. 68—70, Karte; III, 1908, No. 26, p. 56—57). 
75 — A little-known potato disease (The Garden, LXXIV, 1910, p. 560). 
75a — Potato diseases in Ireland (Journ. Dept. Agrie, and techn. Instr. for 
Ireland, X, 1910, p. 241—256, tab.; Farmers Gazette, LXIX, 1910, p. 130). 
76 — and Bowers E. H. Dry rot of the potato tuber (Econ. Proc. Roy. 
Dublin Soc., I, 1909, p. 547 -558) tab. 
77 — and Murphy P. A. A bacterial disease of the Irish potato (Nature, 
London, LXXXV, 1910, p. 296). 
— cfr. Adams John. 
Petitmengin M. cfr. Bonati G. 
78 Petrak Franz. Fungi Eichleriani. Fasc. I, No. 1—25, Mahrisch-Weisskirchen, 
Novbr. 1908. Fasc. II, III, No. 26—75, 1909. - Fasc. IV, No. 76-100, 
Januar 1910. 
79 Petri Lionello. Ricerche sopra la batteriosi dei fico (Rend. Acc. Lincei, 
Roma, 5. ser. XV, 1906, p. 644—651). 
80 — Studii sui marciume delle radici nelle viti fillosserate. Roma (Bertero), 
1907, 40, 148 pp. 9 tab., 25 fig. 
81 — Sur une maladie des olives due au Cylindrosporium Olivae n. sp. (Annal. 
Mycol., V, 1907, p. 320—325) fig. 
82 — Sui disseccamento degli apici nei rami di pino (Annal. Mycol., V, 1907, 
p. 326—332) tab. 
83 — Osservazioni suile galle fogliari di Azalea indica prodotte dall’ Exo- 
basidium discoideum Eliis (Annal. Mycol., V, 1907, p. 341—347) fig. 
84 — Untersuchungen uber die Identitat des Rotzbacillus des Olbaumes (Centrbl. 
Bakt. u. Par., 2. Abt., XIX, 1907, p. 531—538). 
85 — Suile micorize endotrofiche della vite (Atti Acc. Lincei Roma Rend. 
5 ser. XVI, 1. sem., 1907, p. 789—791). 
