TECHNICAL DISCUSSION 167 



(4) LINDQUIST, B. 1941 [Investigations of the importance of some Scan- 



dinavian earthworms for the decomposition of broadleaf litter 

 and for the structure of mull.] (In Swedish, German summary.) 

 Svensk. Skog wards for. Tidskr. 39:179-242. (Abstract in BioL 

 Abs. D16, entry 6276.) 



(5) POWERS, W. L., AND BOLLEN, W. B. 1935 The chemical and bio- 



logical nature of certain forest soils. Soil Sci. 40:321-329. 



(6) Pun, P. C. 1941 Beneficial influence of earthworms on some 



chemical properties of the soil. Sci. Soc. China, BioL Lab. 

 Contrib., Zool Ser. 15:147-155. 



(7) ROBERTSON, J. D. 1936 The function of the calciferous glands of 



earthworms. Jour. Exp. BioL 13:279-297. 



(8) RUSSELL, E. J. 1910 The effect of earthworms on soil productiveness. 



Jour. Agr. Sci. 3:246-257: 

 (8) SALISBURY, E. J. 1924 The influence of earthworms on soil reaction 



and the stratification of undisturbed soils. Jour. Linnean Soc., 



Bot. 46:415-425. 

 (10) STOCKLI, A. 1928 Studien iiber den Einfluss des Regenwurm auf 



die Beschaff enheit des Bodens. Landw. Jahrb. Schweiz 42 :5-121. 



