SCIENCE- GOSSIP. 



The cTolerite in disintegrating, besides forming 

 the ferruginous clay above mentioned, supplies the 

 lime which washes down and forms the travertine 

 beneath the diluvium of the valley, and also gives 

 up some magnesia, which is traced in the well- 

 water of the vicinity. 



The sandstone rocks supjaly the vast quantities 

 of sand which form the greater part of the beds of 

 the larger rivers, sometimes very loose and 

 crumbling, at others stiffened with some of the 

 clay from the dolerite. Occasionally interbedded 

 with the sand, dark carbonaceous patches mark the 

 sites of former vegetation, producing libbon-like 

 dark grej' or black streaks, in the banks of the 

 spruits. 



Eeturning to the older rocks, the sandstones and 

 grits which are found as one ascends from the 

 railway level are seen again on Sussex Hill (see 

 S.-G., map, p. lOi, vol. vii.), and lying loose on these 

 rocks silicified wood, fragmentaxy, is occasionally 

 found. On proceeding S.E. from this hill for 

 about a mile a whole tree was discovered, just above 

 the level of Bloemfontein station, lying in strata 

 of thin sandstones and mudstones. The tree was 

 lying with its roots at a slightly higher level than 

 its branches, having evidently drifted down to this 

 position, where in all probability it still remains, for 

 efforts which were in progress for its removal to the 

 Bloemfontein Museum were cut short through the 

 writer having to proceed to another post. Frag- 

 ments of silicified wood were also observed a little 

 south of Spitz Kop. According to Stow, the 

 Molteno strata were occupied by vast forests of 

 coniferous trees, which are found copiously in 

 certain localities, and generally overlie Coal- 

 measures. 



It ma_y be noted hei-e that a rock described in 

 SCIEN-CE-GOSSIP, vol. vii. p. 34, as appearing like 

 chert was the same as that described on j). 103 as 

 " black, with conchoidal fracture and white streak," 

 and was found afterwards to be carbonaceous 

 shale, metamorphosed by contact with dolerite, 

 the continuation of the same rock near the dolerite 

 being unaffected by the intrusive rock. Since 

 coming to this conclusion, if .suggests itself that 

 the rock described by Stow in " Quarterly Journal 

 Geological Society," vol. xxx., No. 120, p. 620, may 

 be of a similar nature. 



Proceeding northwards from Bloemfontein along 

 the Brandfort Koad, Deale's Farm is passed, just 

 beyond which is the exposure noted on p. 13i of 

 vol. vii. Near this kloof is a flat-topped hill, Plaat 

 Kop. The top of this hill is formed by a dolerite 

 cap ; beneath that is a grit which shows signs of 

 denudation previous to its having been covered, 

 while its upper part has been metamorphosed by 

 the overflow. Beneath the grit come the usual 

 sandstones of varying structure, while in the 

 dongas below the base of the hill blue-grey shales 

 are exposed. Rejoining the road, leaving Plaat 

 Kop on the left, the grass-covered surface of the 



countiy slopes gradually towards the Rhenoster 

 Spruit, which, where the road approaches it, winds 

 through gorges cut through dolerite, its modern 

 banks being formed of brick earth, and lined with 

 plentiful mimosa. Its bed in places shows the 

 doleiite rock. After clearing these hills, shelving 

 diluvial countiy leads down to Glen, on the banks 

 of the Modder River. Here is the bridge for the 

 railway running northwards, blown up by the Boers 

 shortly after the occupation of Bloemfontein by 

 our troops, but now reconsti-ucted. The banks of 

 the river are ,cut out of sand, in which a few sec- 

 tions of mudstones ai'e occasionally visible. These 

 mudstones are well exposed in the bed of the river. 

 The river level here was made to be 4,325 feet ; 

 that of the Rhenoster, where crossed a .short dis- 

 tance above by the road, was 4,375 feet altitude. 

 Wnnhlcdon, February I6th, 1902. 



THE PLUM AND IT8 ALLIES. 



By Sophia Arjiitt. 



"FN March and April, before the great rush' of 

 -^ .spring flowers begins, while they are yet few 

 and therefore precious, only the starry celandine,. 

 violets sweet and otherwise, coltsfoot, gorse, golden 

 saxifrage, mercury, marsh marigold, perhaps a 

 stray primrose or an early windflower, occur the 

 blossoming of many plum trees and the blooming 

 of the blackthorn in the leafless hedges. Gilbert 

 White's date for it is April 7th to May 10th. Other 

 observers have placed it as early as March 16th. 

 In Mr. Preston's " Flora of Wilt.shire " the earliest 

 flowering is February 20th, 1869, and the latest 

 May 5th, 1879. A little later by about a week 

 comes the buUace, and later still the flowers of the 

 wild plum ; but all of them generally bloom in April. 

 These three — sloe or blackthorn, bullace, and 

 plum — are classed together under the common 

 specific name of Primus communis, and separately 

 as sub-species called respectively P. spinosa, P. 

 insititia, P. domestica. The sloe, or blackthorn, is 

 veiy different from the other two. It is thorny 

 while they are not ; its branches spread out at right 

 angles as theirs do not ; .its flowers appear before 

 the leaves, while the others produce flowers and 

 leaves simultaneously. The black fruit of the sloe 

 is upright, round, and sour ; that of the others is 

 hanging, elliptical, or ovoid, and sweet-flavoured,, 

 as well as much larger. The blackthorn is much 

 more abundant and more widely spread in this 

 country; it is wild in Europe only; while the native 

 home of the others is Western Asia and Northern 

 Africa. It is more than doubtful if the wild plum 

 is native to Europe, since in the south, where it is 

 supposed to be so, this species is living in hedges 

 and near dwellings with the appearance of a tree 

 scarcely naturalised. 



Bullace is to be found apparently wild south of 

 the Alps, in Turkey, and the regions round the 



