I50 BOTANICAL GAZETTE [AUGUST 
soils where the reaction is naturally favorable for them. MARCHAL’ 
found numerous mycelia of molds in acid humus soils which were’ 
naturally rich in organic material, and he believed that they took 
an active part in the mineralization of organic nitrogen under 
these conditions, but that in an arable soil under active cultivation 
the molds were relatively few in number owing to the alkaline reac- 
tion and the absence of large quantities of organic matter. While 
the filamentous fungi are naturally thought of as occurring in great 
numbers in acid soils, still the recent work of DALE in England 
indicates that in some cultivated alkaline soils they are just as 
numerous. JENSEN‘ at Ithaca found a great variety of filamentous 
fungi in alkaline cultivated soils. Lately TRAAENS has reported 
the results of his investigation of the species and physiological 
activity of some of the soil fungi of Norway. In our own investi- 
gations on the destruction of cellulose by bacteria and filamentous 
fungi, we worked almost entirely with alkaline soil that had been 
under active cultivation, and found among the fungi occurring in 
both great variety and enormous numbers many species active 
cellulose destroyers. The physiological activities of these organ- 
isms on organic material, whether nitrogenous or not, are well 
recognized. All these data indicate that the filamentous fungi 
are important factors in carrying on the biological processes in 
cultivated soils. 
In further study® of the destruction of cellulose by micro- 
organisms, 19 species of cellulose destroying filamentous fungi 
were identified and two new ones found. One of these species was 
found’ to produce a very active cytase. The present work was 
?Marcuat, Emite, Sur la production de Lounge ot dans le sol par les 
microbes. Bull. Acad. Roy. Belgique ITI. 25:741. 1893. 
3 DALE eons si a fungi of the soil. Ann, Mycol. 10:452-477- Pls. 5- 
TO12: 12: 33-62. pls. 
4 JensEN, C. N. te flora of the soil. N.Y. (Cornell) Agric. Exp. Sta. Bull. 
315. PP. 415-50r. 1912. 
5 TRAAEN, A. na Spyeeicmas iiber Bodenpilze aus Norwegen. Nyt. Mag. 
Naturv. B 52:20-121. pl. 7 
6 McBeth, I. i and Pe F. M., The destruction of cellulose by bacteria 
and Ratatat fungi. U.S. Dept. Agric., Bur. Pl. Ind. Bull. 266. 1913. 
7 KELLERMAN, K. F., Formation of cytase by Penicillium pinophilum. Bur. Pl. 
Ind. Circ. no. ape, PP. 29-31. 1912 
