THE EARTHWORM IN SCIENTIFIC LITERATURE 51 



We decided to leave the box and observe results, meantime cover- 

 ing it for protection against the summer sun and keeping the 

 contents moist. The contents of the box soon lost its identity 

 as manure and after a few months, was found to have been com- 

 pletely converted into fine, dark, crumbly earth. We used this 

 earthworm soil for a Victory Garden, grown in lugboxes, which 

 supplied our table with lettuce, radishes, young onions, beets, 

 and other greens of unusual excellence from early spring until 

 late in the fall. In this instance, the worms brought up consider- 

 able quantities of the subsoil from beneath the old cement box 

 and thoroughly mixed and combined it with rabbit manure, 

 providing us with highly fertile and productive earth for our 

 lugbox garden. 



In the Record of the U. S. Dept. of Agriculture Experi- 

 ment Station, Vol XVII, No. 8*, we find the following sum- 

 mary of an experiment by A. Murinov : 



Alternate layers of different kinds of soil were placed in 

 zinc boxes with one glass side, earthworms were added, the soil 

 kept in a proper state of moisture, and the changes which the 

 soil underwent determined by analyses at the beginning and end 

 of the experiments, which lasted one year. A check series of 

 boxes were treated in the same manner, except that earthworms 

 were not added. 



The results show that in the soils to which the earthworms 

 were added the phosphoric acid soluble in 10 per cent hydro- 

 chloric acid increased in all cases. The lime content, which at 

 the beginning was greatest in the surface soils, was found at 

 the end of the experiments to gradually increase from the sur- 

 face toward the subsoils. The nitrogen was more uniformly 

 distributed throughout the soil at the end of the experiment than 

 at the beginning. 



In considering soil that has been worked over by earthworms 

 and mixed with earthworm castings, attention should be called to 

 the fact that the major plant- food elements nitrogen, phos- 



*Page 744 



