HARDWICKE'S SCIENCE-GOSSIP. 



189 



principal stems and surrounded by double flowers of 

 the normal buff colour, was a solitary red single 

 flower. There was no mistake about it, and no cause 

 such as grafting or budding to account for it. The 

 single flower was perfect, and as bright and pure in 

 colour as if it had grown on a red hibiscus shrub. I 

 have tied a thread round the stem which bore it, to 

 see if any more single or abnormal coloured flowers 

 will appear on it. — IV. J. S., Cakitita. 



GEOLOGY, &c. 



The Geology and Mineralogy of Mada- 

 gascar. — Dr. G. W. Parker has just contributed a 

 paper on this subject to the Geological Society. A 

 central plateau from 4000 to 5000 feet high occupies 

 about half the island, rising above the lowlands that 

 skirt the coasts, and from this plateau rise in turn a 

 number of volcanic cones, the highest, Ankaratra, 

 being 8950 feet above the sea. The known volcanic 

 cones extend from the northern extremity of the 

 island to the twentieth parallel of south latitude. 

 Beyond this granite and other primitive rocks occur 

 as far as lat. 22°, south of which the central parts of 

 Madagascar are practically unknown to Europeans. 

 Only a single trap-dyke is known near Antanarivo. 

 The hills around this city are of varieties of granite. 

 The general direction of the strata is parallel to the 

 long axis of the island. Marine fossils have been 

 found, by Rev. J. Richardson and Mons. Grandidier, 

 in the south-west part of the central plateau. These 

 fossils are referred by the last-named tiaveller to the 

 Jurassic system. Remains of hippopotami, gigantic 

 lortoises, and an extinct ostrich-like bird have also 

 been recorded. North and north-west of the fossili- 

 ferous rocks, between them and the volcanic district 

 of Ankaratra, sandstone and slate occur. North of 

 this volcanic district again is a tract of country in 

 which silver lead (mixed with zinc) and copper are 

 found. Near the north-western edge of the central 

 plateau are granitic escarpments facing northwards 

 and about 500 feet high. Some details were also 

 given of valleys through the central plateau and of 

 ilagoons within the coral reefs on the coasts. 



The Oolitic Rocks under London. — Professor 

 Judd has recently made an additional communication 

 on this interesting subject to the Geological Society. 

 The well-boring at Richmond has now been carried 

 down to a depth of more than 1360 feet, 220 feet 

 deeper than has been reached by any other boring in 

 the London Basin. A temporary cessation of the 

 work has permitted Mr. CoUett Homersham to make 

 a more exact determination of the underground 

 temperature at Richmond. At a depth of 1337 feet 

 from the surface, this was found to be 752° F., 

 corresponding to a rise of temperature of 1° F. for 

 every 52 '43 feet of descent. The boring is still being 



carried on in the same red sandstones and "marls," 

 exhibiting much false-bedding. The Rev. H. IL 

 Winwood, of Bath, has found the original fossils 

 obtained by the late Mr. C. Moore from the oolitic 

 limestone in the boring at Meux's Brewery in 1878. 

 A careful study of these proves that though less 

 numerous and in a far less perfect state of preserva- 

 tion than the fossils from the Richmond well, they in 

 many cases belong to the same species, and demon- 

 strate the Great Oolite age of the strata in which they 

 occurred. Dr. Hinde has described five new species 

 of Calcispongia from the materials brought up by the 

 boring. One species is closely allied to Blastinia 

 costata from the lower Jurassic strata at Streitburg. 

 Professor Rupert Jones also described the Foraminifera 

 and Ostracoda, and Mr. G. R. Vine the polyzoa 

 found at the Richmond well-boring. The polyzoa 

 included fourteen different forms, most of which are 

 characteristic of the oolite, and some of which are 

 new. 



The Underground Geology of Northampton. 

 — At a recent meeting of the Geological Society, Mr. 

 H. J. Eunson, F.G.S., read a very important paper 

 on the " Range of the Palaeozoic Rocks beneath 

 Northampton." In two borings made near the 

 town by the local water company, after passing 

 through 738 feet of the upper, middle, and lower lias, 

 a series of conglomerate sandstone and marls were 

 found resting on an eroded surface of carboniferous 

 dolomite, passing into the usual fossil-crowded lime- 

 stone. Forty-six feet of carboniferous strata were 

 drilled, and the boring was discontinued at 851 feet. 

 A second boring at a place called Gay ton, after passing 

 through various strata, came upon an eroded surface 

 of carboniferous limestone at a depth of 699 feet. In 

 this fossils were found down to a depth of 889 feet, 

 the boring being continued to a total depth of 944 

 feet. At Orton, near Kettering, a boring was made 

 through white lias, rhaetic, sandstone, and breccia, 

 into quartz-felsite in a futile search for coal. As none 

 was found down to a depth of 789 feet, the boring 

 was discontinued. 



The Geologists' Association. — No. 6 of vol. 

 viii. of the " Proceedings" has just been published. 

 It contains the following papers (besides notices of 

 meetings): "Fossil Plants," by J. S. Gardner, 

 F.G.S. ; "Fossil Plants from various Formations," 

 by W. Fawcett, F.L.S. ; " Notes on the Krakatoa 

 Eruption," by Grenville A. J. Cole, F.G.S. ; "The 

 Implementiferous Gravels of North-east London," by 

 J. E. Greenhill ; and another on the " Implement- 

 iferous Gravels near London," by Professor T. 

 Rupert Jones, F.R.S., &c. 



Fasciated Stem in White Broom. — There is 

 now growing in my garden a plant of white broom, 

 one branch of which is fasciated till it is three-quarters 

 of an inch wide, — K. D., Co/ton. 



