284 PATHOLOGY [BoT. Absts., Vol. X, 



1865. RiTZEMA Bos, J. Trametes Pini Brot. (Fr.) een voor de dennen hoogst gevaarlijke 

 zwam, thans ook in Nederland aangetroffen. [Trametes pini, a fungus very dangerous to the 

 fir, now present in Holland.] Tijdschr. Plantenz. 26: 189-192. 1920. — The author records 

 the recent discovery of this fungus in Holland and describes the character of the injury to 

 the host.— fl". H. Whetzel. 



1866. ScHOEVEKS, T. A. C. Nieuwe ziekten, waarop gelet moet worden. [New diseases 

 to which attention should be given.] Tijdschr. 'Plantenz. 26: 208-211. 1920. — The discovery 

 in Holland of the disease of beans caused by Isariopsis griseola is recorded. — H. H. Whetzel. 



1867. South, F. W. Short report on the work of the inspection staff, second half-year, 1920. 

 Agric. Bull. Federated Malay States 8: 256-258. 1920 [1921].— During the dry weather of the 

 3rd quarter of 1920 moldy-rot disease on the rubber tree {S phaeronema fimbriatum) became 

 less abundant and in some places disappeared. A dying-back of the edge of the tapping cut 

 on trees of Hevea brasiliensis, as well as a decay of the renewing bark, of obscure cause, was 

 observed. Ustulina zonata was observed on Areca catechu. — I. H. Burkill. 



THE PATHOGENE (BIOLOGY; INFECTION PHENOMENA; DISPERSAL) 



1868. BtJSGEN, M. Omnivorie und Spezialisation bei parasitischen Pilzen. [Omnivorous- 

 ness and specialization among parasitic fungi.] Zeitschr. Forst- u. Jagdw. 51: 144-153. 1919. 

 — Specialization by parasites is said to be the resultant of the individual capability of the 

 parasite and the nature of the host plant. It is first manifested in the ability of the fungus 

 to penetrate the cell-wall, which offers the first resistance. Botrytis vulgaris, a very im- 

 portant destroyer of forest trees, decomposes cellulose readily, but it is limited as to its ability 

 to break down the cell structure of various plants. Once it breaks through the cell structure 

 it is omnivorous. The poison from the fungus, which is not oxalic acid, brings about loss of 

 turgor, and death, and separation of cells. Plants immune to infection usually have leaves 

 with smooth, shiny, waxy epidermis. — J. Roeser. 



1869. Harter, L. L., and J. L. Weimer. Studies in the physiology of parasitism with 

 special reference to the secretion of pectinase by Rhizopus tritici. Jour. Agric. Res. 21: 609- 

 625. 1921. — Rhizopus tritici acts in advance of its growth in sweet potato [Ipornoea], causing 

 a dissolution of the cells. The fungus produces a powerful intracellular and extracellular 

 enzyme, pectinase, when grown in sweet potato decoction. The maximum enzyme content 

 of the hyphae and of the nutrient solution is attained in cultures about 24 and 48 hours old, 

 respectively. The extracted enzyme effects complete maceration of raw sweet-potato discs. 

 It acts most rapidly at temperatures between 45 and 55°C.; below 45°C., its action decreases 

 directly with the temperature. The enzyme is inactivated at 60°C., and is slightly deactivated 

 by centrifuging to remove sand and fungous debris, and by filtering the solution — in which 

 powdered hyphae and sand are suspended — through filter paper. Exposure of the fungus 

 hyphae to direct sunlight for 2 hours does not affect the macerating power. The enzjone is 

 not affected by toluol (when used as a disinfectant), by washing in water for 15 minutes, or 

 by treating with acetone for 12 minutes followed by ether for 3 minutes. — D. Reddick. 



1870. TuRESON, GoTE. Mykologisks Notiser II. [Fusarium viticola Thiim infecting 

 peas.] Bot. Notiser 1920: 113-125. Fig. 1. 1920. — A severe infection appeared in 1918 at 

 the experimental station at Svalov, Sweden. The varieties of peas attacked most severely 

 in 1918 were: Non plus Ultra and Stensarl;; less so Gradus, Non Pareil, and Champion of Eng- 

 land. — Mycelium was found in fissures of the stem. When transferred to culture media, 

 Aspergillus, Penicillium, Cladosporium, Macrosporium, and Fusarium viticola Thiimen were 

 isolated. The inoculations with Cladosporium and Macrosporium yielded negative results. 

 Peas were germinated in moist sawdust at a temperature of 15-18°C., the following field-peas 

 being used: Concordia, Gropart, Soloiirt; and of garden peas the marrowfats Non plus Ultra, 

 Stensart, and Champion of England. The results of 3 kinds of inoculation were as follows: 

 (1) Soil-infection gave positive results in all varieties, some garden-peas (Stensart, Champion 



