Hubert M. Mokris 305 



manured or not. The most notable exception to this ii;enerahsation is 

 met with in the Diplopoda, whose numbers are increased by about 200 per 

 cent, in the manured plot. 



(0 



(7 

 (8 



(9 

 (10 



(11 

 (12 

 (13 

 (14 



REFERENCES. 



Darwin, C. (1881). Vegetable Mould arid Earlhworms. London, John Murray. 

 Djemil, — (1898). Ber. Physiol. Lab. Vers. Halle. (Referred to by Hilgard (7).) 

 DussERRE, C. (1902). Influence des vers de terre sur la composition chiniique 



du sol arable. Ann. Afjric. de la Suisse, in. 2.3-28. 

 Fowler, C. (1889). Brilish Coleopiera, m. 304. 

 Hamilton, C. C. (1917). The behavior of some soil insects in gr.ulicnts of 



evaporating power of air, carbon dioxide and ammonia. Biol. Bull. 



xxxn. 159. 

 Hensen, M. (1877). Die Thatigkeit des Regenwurms flir die Fruchlnukeit des 



Erdbodens. Zeilschr. Wiss. Zool. xxvuL 354-364. (Account in Nature, xvii, 



1877, 18-19.) 

 Hilgard, E. W. (1914). Soils. Mac millan Company, New York. 

 KosTiTCHEFF, P. (1886). Potsckvi tschernozemskoi oblasti Rossii. Petrogi-ad 



(Abstract in Ann. Sci. Agronom. ii. 1887, TiCS terres noires de Russie, 165-191.) 

 KosTiTCHEFF, P. (1889). Rcchcrches sur la formation et les qualites de I'humus 



(Translation). Ann. Agronom. xvit. 1891, 17-38. 

 Morris, H. M. (1920). Observations of the insect fauna of permanent pasture 



in Cheshire. Ann. Ajrp. Biol. vii. 2 and 3. 

 Morris, H. M. (1922). On a method of separating Insects and other Arthropods 



from soil. Bull. Ent. Res. xm. 197. 

 Russell, E. J. (1910). The effect of earthworms in productiveness. Journ. 



Agric. Sci. in. 1908-10, 246-257, 2 tigs. 

 Hteglitz, — (1911). Fiihling's Landw. Zig. Lx. No. 15, 538-542. (Abstract in 



Expt. Sta. Rec. xxv. 1911, 817.) 

 WoLLNY, — (1890). Forsch. Agr. 382. (Referred to by Hilgard (7) ) 



(Received April 3rd, 1922.) 



Ann. Biol, ix 20 



