1^0 Transactiotis. — Zoology. 



brick Avas strewed on the surface, above tbe former layer, and a 

 similar strip of debris was also scattered in a grass paddock 

 on tbe upper land, ordinary light clay soil, with a moderately 

 hard subsoil. Although the spot selected was rather favour- 

 able for earth-worms to work in, the amount of castings 

 ejected on the surface may be taken as a fair average for 

 the whole field. Sheep were occasionally grazed in the field ; 

 but considering how soon small fi.-agments disappear beneath 

 the surface, probably their treading did not much influence 

 the result. 



Owing to there being no well-defined line between the 

 dark mould and substratum, no estimate of any value can 

 be given as to the probable amount of subsoil that has 

 been brought to the surface durmg the past three years ; but 

 a record will be kept of any marked increase in the depth 

 of the vegetable mould, the average depth now being about 

 5f inches. At the present time the section in the trench 

 shows, the grass being shaved off close to the surface, an 

 average of f ths of an inch of brownish-black mould, fi-ee from 

 coarse material, and a horizontal layer of charred wood and 

 broken brick half an inch thick, forming an even line round 

 the vertical sides. This means that in three years, or rather 

 during the working months of that interval, through the 

 agency of earth-worms, f ths inch of mould has been added to 

 the superficial layer — mould that has been enriched with 

 vegetable and animal matter, passed the bodies of the worms, 

 and ejected as castings on the surface. 



This annual working of the superficial mould effects a remark- 

 able change in the character of our fern-lands in the course of 

 lime^ — that is, after they have been cultivated, or, more especially, 

 if left in permanent pasture for 10-15 years, and have become 

 fairly stocked with worms. There are, no doubt, other 

 agencies that, under the circumstances, tend to improve the 

 soil, but, more particularly in the case of permanent pastures, 

 only minor agencies. 



From the number of earth-worms that live in most of our 

 old pasture-lands, it is evident — independently of the experi- 

 ment given above — that, as Mr. Darwin has shown, the super- 

 ficial mould must pass over and over again through their bodies, 

 and be brought to the surface. It is hardly necessary to point 

 out the value such work must be to the agriculturist, especially 

 when taken in conjunction with the loosening of the subsoil by 

 their burrows and chambers, which in time become more or 

 less filled up with their castings and the dark viscid linings of the 

 walls. These moist and nourishing galleries, penetrating, as a 

 rule, to a depth of 6-15 inches beneath the surface, must tend 

 to draw the roots of the vegetation to a depth that they would 

 }iot otherwise attain. 



