410 Transactions. — -Geology. 



particles of earth as can be moved between the coarser 

 particles of the mass, and these fine particles are of 

 course deposited on the sides of the fissures when the 

 water evaporates. The fissures, once formed, remain planes 

 of weakness, the ground cracks in the same lines year 

 after year, and in course of time a considerable thickness 

 of fine material may be thus separated from the mass and 

 collected upon the sides of each clay prism. (Is the whiteness 

 of the veins due, wholly or in part, to a bleaching-power in the 

 water which filters into them from the soil when a rain 

 occurs '?) In the present subsoil at Timaru these white veins 

 range up to l^in. in width, between prisms of clay not exceed- 

 ing 2ft. in longest diameter, and they extend downwards as 

 much as 8ft. or 10ft. in some places. In the lower portion of 

 the loess there are two or more series of these veins, the 

 highest terminating above in a granule-band about 10ft. above 

 the rock. There is another terminated by the second well- 

 marked band from the surface. There may be other series : 

 the cuttings are too much hidden by rain-wash to allow one to 

 see. If there were any possibility of mistaking the veins in 

 vertical sections, there can be no mistaking the characteristic 

 pentagonal forms seen in horizontal sections. The existence 

 of these veins supports the testimony of the granule-bands as 

 to the occurrence of long pauses in the deposition of the loess. 

 But, while the granule-bands seem to indicate a wet climate, 

 the evaporation-veins indicate a dry one, and to accept the 

 contradiction and explain it we must suppose the pause was 

 sufiiciently prolonged to permit of a complete change of 

 climate, either from wet to dry, or from dry to wet. 



"Bird-stones." — It would be reasonable to suppose that 

 the surface peat-pool cut into by the engine-shed excavation was 

 formerly more or less frequented by water-fowl, and that they 

 would leave lasting vestiges of their visits or sojourn there in 

 the shape of ejected gizzard-stones. As a matter of fact, they 

 have done so. Many small stones, well worn — unquestionable 

 "bird-stones" — can be picked out of the clay immediately 

 beneath the ashes of the burned peat-bed. The same expecta- 

 tion might be formed regarding the buried peat-pool ; and it 

 would be fully justified, for these vestiges of the water-fowl 

 of the period are immeasurably more numerous there than 

 similar ones in the surface-hollow. The majority of the stones 

 are small, though larger than those in the upper bed, but 

 among them are some the size of common marbles. Large 

 and small, there must be a bushel or two of gizzard-stones 

 buried with this old water-hole, the section of which is only 

 about 20 yards long, and the stratum representing the pool 

 ojily 12in. or 15i]i. thick. The same proofs of the existence of 

 l)ird-life are to be found throughout the deposit, from the clay 



