42 



XIX. H. B. Hutchinson and J. Clayton. " On the Decom- 



position or Cellulose by an Aerobic Organism 

 (Spirochceta cytophaga n. sp.).'' Journal of Agricul- 

 tural Science, 1919/ Vol. IX. pp. 143-173. 



Kxaniination of Rothamsted soils on different occasions has 

 revealed the presence of an organism capable of breaking down 

 cellulose with comparative ease. Morphologically, the organism 

 appears to possess greater aflinities with the Spirochaetoidese than 

 with the bacteria, and the name Spirochceta cytophaga is therefore 

 suggested. 



Wliilc the Spirochait is capable of considerable vegetative 

 growth as a sinuous filamentous cell, it also appears to pass 

 through a number of phases which terminate in the production of 

 a spherical body (sporoid) which differs in a number of respects 

 from the true spores of the bacteria. Germination of the sporoid 

 again gives rise to the filamentous form, which possesses perfect 

 tlexibility and is feebly motile. The latter does not apparently 

 possess flagella. 



Spirochceta cytophaga is essentially aerobic ; its optimum tem- 

 perature is in the region of 30". Both the thread and sporoid 

 stages are killed by exposure to a temperature of 60° for ten 

 minutes. 



The nitrogen requirements of the organism may be met by a 

 number of the simpler nitrogen compounds — ammonium salts, 

 nitrates, amides and amino-acids. Peptone is also suitable in con- 

 centrations up to 0.025%. Stronger solutions, e.g., 0.25% lead 

 to a marked inhibition of growth. The organism fails to grow en 

 the conventional nutrient gelatine or agar. 



Comparative experiments with a number of higher alcohols, 

 sugars and salts of organic acids show that none of these is 

 capable of meeting the carbon requirements of the organism. 

 Cellulose is the only carbon compound with which growth has been 

 secured. 



Although none of the monoses, bioses and other carbohydrates 

 is able to support growth, many of them exert an inhibitive action 

 on cellulose decomposition if present in other than very low con- 

 centrations. This may be correlated with the reducing properties 

 of the carbohydrate. Maltose, for example, has been found to be 

 approximately 70 times more toxic than saccharose. 



Of the various by-products of the action of Spirochasta 

 cytophaga may be mentioned : (a) a pigment possessing relations 

 to the carotin group, (b) mucilage which does not give rise to 

 optically active compounds on hydrolysis, and (c) small quantities 

 of volatile acids. 



Evidence is also adduced to show the relation of cellulose de- 

 composition to the assimilation of atmospheric nitrogen. 



XX. A. W. RvMER RoBKRTS. '' On the Life History of 



Wireworms of the genus Agriotes, Esch., with 



some Notes on that of Athous H.emorrhoidalis, 



F." Part T. Annals of Applied Biologv, 1919. Vol. 



VI. pp. 116-135. 



The biology and life history of the common ** wireworm " 



was studied during the years 1916-1919. In England and probably 



also in Wales and Scotland, Agriotes ohscurus is generally the 



