GEOLOGY AND MINERALOGY OF NATAL. 'I27 



buffaloes used to roll in bye-gone days. (2) They mark the sites 

 where natives used to dig for iron ore for the manufacture of their 

 weapons. (3) They represent the ancient " gold diggings " of the 

 early Australian prospectors in this country. (4) They have been 

 produced by percolating waters. After a careful study of the 

 " Wallows," I regret that I cannot accept any of these theories for 

 they do not appear to be supported by geological facts or evidence. 

 In other parts of the Colony, where elephants and buffaloes were 

 Icnown to have been more numerous, such " Wallows " are not to 

 be found. I may say that it is in the south of the Colony that 

 they occur. A careful examination of the underlying strata shows 

 that there are no rocks under them from which the natives could 

 have obtained iron for their instruments. Nor are there any such 

 rocks adjacent to them. Hence it would appear that theories (i) 

 and (2) are based principally on historical evidences and traditions 

 which are little more than native superstitions. Number (3) has, 

 however, some evidence to support it. There are throughout 

 these parts of the country certain ancient workings which were no 

 doubt made by early " gold seekers." These, however; may be 

 classed as perfectly distinct from those that I refer to. There is 

 something about them that at once reveals that they are the work 

 of man. They are pits or furrows too, but there is a regularity in 

 their construction, and they have been made symmetrical. There 

 is almost an entire absence of earth worms from their slopes or 

 ridges. They are made usually across the outcrops of the leaders 

 and not elsewhere. The most convincing proof of all is the fact 

 that the ridges between them are made of pieces of rocks taken 

 from the quartz leaders and are not sand and clay as in the case of 

 the " Wallows." As regards theory (4), I have failed to find any 

 trace of evidence to give even a foundation to such a theory. I 

 think that these " Wallows " are the work of the earth worms 

 alone. Their efforts may have been assisted by surface waters. 

 It is true earth worms are to be found in other tracts on the same 

 kind of soil, but there are no " Wallows " there. This is due to 

 the soil there being beyond the average depth at which " Wallows ■" 

 could come into existence and is thus no impediment to the theory 

 I now put forward. The earth worms seem to work more in wet 

 or moist weather than in dry weather. Wet soil is more suited to 

 them for throwing up their " castings." They have a tendency to 

 congregate in colonies. When the soil appears to be less than three 

 feet in depth the " Wallows " originate through their congregation 

 in colonies. They abstract the soil from the ground and make 

 their castings above the surface. Owing to the clayey nature of 

 the soil these castings though wet when first thrown up soon become 

 very dry and hard. Even the most violent winds and heavy rains 

 and storms do not interfere with them ; nor do they become defaced 

 or washed away. Consequently this action at once gives rise to 

 miniature ridges in the sites of the colonies with slight hollows in 

 between. The rate of the conversion of the underlying rocks into 

 subsoil is very slow. It is considerably slower than the rate of the 

 conversion of the subsoil into soil and than the rate of the abstraction 

 of the soil from the earth by the earth worms. In course of time 



