214 



iVA TURE 



[December 28, 1905 



Maclver. Mr. Mather visited sites at Inyanga, Niekerk, 

 N'Natali, Umtali, Dhlo-Dhlo, Kami, and Zimbabwe, views 

 of all ul which were shown. At Inyanga there are count- 

 less "pit dwellings," consisting of a pit and passage and 

 hut platforms. The elucidation of the mystery of their 

 use is assisted by a study of the Niekerk ruins, which are 

 the must remarkable in the country. The area of these 

 ruins is not less than fifty square miles, and within this 

 area il is almost impossible to walk mure than ten yards 

 without coming upon a wall. The general principle appears 

 to l>e thai each hill constitutes a separate unit complete 

 with its own buildings and divided at the bottom from its 

 neighbour by a boundary wall, which is the first of a series 

 of concentric lines. These lines cannot have been for pur- 

 poses of irrigation, but must have been entrenchments. 

 The} always cease at the crown of the hill, which is 

 covered by ■> series ul buildings, and it is this fact which 

 shows the bearing of these walls in the problem of the pit 

 dwellings. The buildings in the hill are of two types, one 

 divided by successive stages from the pit dwelling and the 

 othei the pit dwelling itself. The furls at Niekerk are 

 also generally of similar or derived form to those at 

 Inyanga. Similarly, the more advanced type of buildings 

 found at Umtali or elsewhere are all derivatives of the 

 pit dwelling, and Great Zimbabwe itself falls into line, and 

 was simply a royal kraal. In the whole country there 

 sei is to be a regular progression with regard to these 

 buildings, the northern region being the most fortified, and 

 the defensive scheme becoming less rigorous towards the 

 south. As to the buildings of these forts and dwellings, 

 ali the implements found are of the type used by the 

 native of the present day, and as at Niekerk there is 

 no evidence of modern squatting it seems fair to presume 

 thai similar implements found elsewhere are also not the 

 results of squatting, but were left by the original builders. 

 As to the date, Mr. Maclver cut sections in the ruins he 

 visited, and at Dhlo-Dhlo he made a most significant and 

 conclusive discovery. A trench was cut below the intact 

 cement floor of a hut, and amongst other objects Mr. 

 Ma; [ver discovered fragments of Nankin china. Con- 

 sequently, no stone was laid at Dhlo-Dhlo before the time 

 when Nankin china was manufactured and imported from 

 the Kasi ; experts fix this date as the sixteenth century a.d. 

 This find conclusively fixes the date, for Dhlo-Dhlo and 

 II the other remains exhibit similar characteristics of 

 building, and it may be taken as proved that the ruins 

 (-1 Rhodesia are mediaeval or post-mediaeval, that they 

 ■ anni i be possibly placed earlier than the eleventh century 

 (probably the very oldest building was not erected befon 

 the fourteenth century), and that they were built by a 

 native African race not differing to any great degree from 

 the modern natives. 



Entomological Society, December 0. — Mr. F. Memfiehl. 

 president, in the chair. — Exhibitions. — A series of varieties of 

 the Mediterranean Carabus morbillosus, showing all inter- 

 gradations from the ordinary morbillosus, and presenting 

 a striking case of geographical variability: Dr. K. Jorcfan. 

 Specimens of Ptinus pusillus, Stwem., recently dis- 

 covered in a cum factor's shop at Edmonton : H. St. J. 

 Donisthorpe. — A hermaphrodite of the Proctotrupidae, 

 a sand-wasp without wings captured by Mr. Poole, 

 and the S Apion semivittatum , Gyll., taken manv 

 years ago by Mr. Walton near the ["ivoli Gardens, 

 Margate, together with a 5 specimen of the same species 

 <ii- i vend while -weeping long grass near the Chequers 

 Inn. Deal, on September 26, K104: A. J. Chitty. — A 

 and example of the Dipterun Helophihts transfugus, 



I... taken from thistle-heads in the fen marshes at Edmon- 

 ton lasi July, and a specimen ol Stcnopteryx hirundinis, 

 a parasite on swallows and martins found on Box Hill, 

 Surrey, in August : F. B. Jennings. — Specimens of 

 Odontopera bidentata ab. nigra, the melanic form of which 

 is rapidly increasing in the Wakefield district of south 

 Yorkshire: (i. I. Porritt.— Specimens of South African 

 Pierine butterflies taken in the dry season this vear, further 

 illustrating the diverse forms, and with them, for com- 

 parison, specimens taken during the rains : Dr. F. A. 

 Dixey. — A •' and specimen of Ornithoptera rlihtnur,i . 



Rothschild, and some remarkable species of Delias collected 



'!> b) Mr. \ S Meek in the mountain region of 



NO. 18S7, VOL. 73] 



British New Guinea : O. E. Janson. — Specimen of a 

 Buprestid beetle, Cyriu imperialis, Don., having, in addi- 

 tion to the normal fore-leg on the left side, two supple- 

 mentary fore-legs originating from separate coxae : Com- 

 mander J. J. Walker, on behalf of Mr. A. M. Lea. — 

 c3" and v examples of Tetropium craivshayi, Sharp, bred 

 by the Rev. G. A. Crawshay from eggs deposited in July 

 last in the bark of larches at Leighton Buzzard : G. C. 

 Champion. — Unique specimen of Depressaria emeritella. 

 Sin., from an unknown locality, cm which the species was 

 added to the British list manv years ago, and a specimen 

 of Cerostoma asperella, 1.., discovered by Mrs. Hutchinson 

 near Leominster on September 21, 1881, and only taken, 

 as regards Britain, in Dorset (formerly), and Herefordshire 

 very rarely : E. R. Bankers. — Series of Tryphaena comes 

 bred through three generations, and brought together to 

 test the relative proportions of melanic to non-melanic 

 forms and the possible range of variations to be- obtained 

 from a single pair of parents : A. Bacot. The exhibitor 

 announced that all the results of the second and third gener- 

 ations seemed to be capable of " Mendelian " explanation. 

 — (1) Larv;e of Collyris emarginatus, Dej., from Borneo, 

 observed with mouth-parts qualified to excavate burrows in 

 wood. (2) Larvae and pupte of Mormolyce, together with a 

 specimen of a fungus of Polyporus split open to show the 

 lenticular chamber excavated by the larva, to which access 

 was obtained by so small an orifice that it was surprising 

 that the emerged beetle could squeeze through : R. 

 Shelf ord. — Papers. — Some observations by Mr. A. H. 

 Hamm, of the Hope department, Oxford University 

 Museum, tending to confirm the opinion that Pieris rn^n- 

 chooses for prolonged rest a surface on which it will be 

 concealed : E. B. Poulton. — On the emergence of 

 Myrmelaon formicarius : W. J. Lucas. — Descriptions of new 

 species of African Halticinae and Galerucinae : M. Jacoby. 

 — On the ichneumonidous group Trypkonides schizodonti, 

 Holmgr., with descriptions of new species : C. Morley. 



Linnean Society, December 7 — Prof. W. A. Heiilman, 

 F.R.S., president, in the chair. — On the atiologv of 

 leprosy : Dr. J. Hutchinson, F.R.S. The author adduced 

 much evidence from all parts of the world in support of 

 the fish hypothesis of the cause of leprosy, more especially 

 from South Africa, China, and Norway. In places where 

 the disease is scattered and infrequent there might, he 

 admitted, be some difficulty in tracing the association of 

 cause and effect ; but if regard be taken of those only in 

 which excessive prevalence occurs, all hesitancy would dis- 

 appear. He challenged anyone, not yet convinced, to name 

 any place in the whole world in which the leprosv pre- 

 valence exceeded 50 per 10,000 which was nut either a 

 fishing-station or notorious for the consumption of bad 

 fish. As instances of places where this enormous preva- 

 lence has been recorded, the following were mentioned : — 

 Minicoy (Maldives), Kalagoan (Bengal coast), Fiji, and the 

 Sandwii b Islands. By way of affording a standard of 

 comparison, it was added that the prevalence in Ceylon 

 was only 2 per to, 000, and in India as a whole less 

 than 0. 



Paraday Society, December 12. — Mr. James Swinburne, 

 vice-president, in the chair.— The physics of ore flotation: 

 J. Swinburne and Dr. tj. Rudorf. The flotation of ores 

 to separate them from gangue is carried out by treating 

 them with dilute acid, or acid sodium sulphate, at a 

 temperature short of boiling water. Little bells of CO., 

 attach themselves to the ore particles, but not to the 

 gangue, and the ore particles are floated to the surface, 

 where they are skimmed off. The' questions are why the 

 sulphides an selected, and why the temperature matters. 

 The authors hold that it is a question of two opposing 

 fi He- adhesion between the solids end the liquid which 

 vari s with different solids and liquids, and surface tension 

 of the liquid. — The concentration of metalliferous sulphides 

 by flotation : Prof. A. K. Huntington. The paper also 

 embodies the author's contribution to the discussion on 

 the previous paper. Experiments are described which prove 

 that the gas causing flotation is CO, derived from native 

 carbonates of iron and manganese present in the ore, and 

 not from calcite or from carbonates produced on the surface 

 of the sulphides by weathering. Carbonates which are 

 decomposed by dilute sulphuric acid in the cold do not 



