xVIay 12, 1S92 



NA TURE 



47 



the natural food-plant, were shown by Mr. J. A, Simes, Mr. A, 

 Quail, and Mr. A. J. Croker, the latter gentleman's Phoro- 

 iiesma smaragdaria being especially noticeable. Mr. R. Adkin 

 exhibited a collection of British Sphinges and Bombyces, 

 arranged with a view to showing local variation, such variation 

 being well defined in some of the species of the genus Spilo- 

 soma. ANo a collection of Macro- Lepidoptera made at 

 Rannoch, Perthshire, in.iSgi, illustrating an article on the 

 local variation prevailing in that district recently contributed 

 to the Enlomolo^st. Mr. Tutt, extremely long and variable 

 series of NoctU£E. Mr, Machin four drawers from his cabinet ; 

 among the rarer species were Dicratmra ticuspis and Drepana 

 sicula. 



In the third room there was a large exhibit of marine 

 Mollusca, by Mr. Conisbee. Mr. Step's exhibit of living 

 Mollusca afforded a capital opportunity for comparing the 

 mollusks as well as their shells. Between thirty and forty species 

 were thus shown, each in a separate glass, and ranged from 

 the substantial Helix pomatia to the graceful Clatisilia rugosa 

 among land snails ; and from the large Anodons to the fragile 

 Planorbis linentus among the aquatic species. Pond life was 

 shown by Mr. Perks ; living newts, &c., by Mr. R. Adkin, Jun. ; 

 and living snakes, &c. , by Mr. Gee. A gigantic sponge was 

 exhibited by Mr. Kedgley. 



In a fourth roam Mr. Reeves exhibited and explained an 

 original set of diagrams, showing the correct positions of hordes' 

 legs while walking, trotting, and galloping, and to demonstrate 

 their correctness the diagrams were transferred to a zoetrope. 



A large room was set apart for lectures, and during each 

 evening crowded audiences listened to Mr. F. Enock, who 

 lectured on "The I.ife-history of the British Trap-door Spider." 

 The lecture was illustrated by Mr. Knock's original micro- 

 photographic slides, shown by means of the oxy-hydrogen 

 lantern. Mr. E. Step's " Talk about Toadstools " was listened to 

 attentively on each evening. The figures thrown on the screen 

 were from Mr. Step's own photographs and drawings. A third 

 lecture was given by Mr. George Day, illustrated by micro- 

 photographic slides, entitled "Domestic Friends and Foes." 



I M ERIN A, THE CENTRAL PROVINCE OF 

 MADAGASCAR. 

 /^N Monday evening the Rev. James Sibree read a valuable 

 ^^ paper on Imerina, the central province of Madagascar, 

 before the Royal Geographical Society. After an account of 

 the work of recent explorers, of whom the French surveyors, 

 MM. Catatand Maistre, and the English missionary, Mr. Baron, 

 are the most important, Mr. Sibree came to the main subject of 

 his paper, of which the following is an abstract. 



M. Grandidier, who is now completing a splendid atlas of 

 Madagascar, published a map of Imerina on the scale of 

 I : 200,000 in i88o, and in 1883 an orographical map coloured 

 according to the contour lines. The road from the port of 

 Tamatave to Antananarivo, the Hova capital, in the centre of 

 the Imerina province remains a mere footpath, impassable 

 either to wheeled vehicles or to beasts of burden ; and now, as 

 300 years ago, porters are the only means of transport. 



Imerina ("the elevated ") is bounded on the east by the steep 

 ridge of forest-girdled mountain sloping to the Indian Ocean. 

 The other boundaries are indistinct, and the total area of the 

 province may be estimated at 7000 square miles. The general 

 level of the province is from 4000 to 4500 feet above the sea. 

 It is a mountainous region, abounding in peaks, which rise high 

 above the breezy plateau, and marked also by many valleys. 

 The most prominent summits are Angavokely to the east, 

 Ambohimiangara in the extreme west, Iharanandriana to the 

 south, Milangana, Ambohimanoa, and Andringitra more cen- 

 tral, and Ambohipaniry and Vohilena to the north. The south- 

 west of the province is dominated by the central mass of 

 Ankaratra, a denuded volcano of great size, its peaks forming the 

 culminating points of the island, and reaching nearly 9003 feet 

 above the sea. The mountain-peaks are usu.illy granite or gneiss, 

 sometimes occurring in great rounded bosses, sometimes in fan- 

 tastically carved pinnacles resembling from a distance Titanic 

 forts, castles, and cathedrals. Decomposed granite covers a 

 great part of the country with thick deposits of clay, sometimes 

 white but more often tinted deep red by ferric oxide. Iron is 

 abundant, gold has recently been discovered, graphite, galena, 

 copper, and other useful minerals are also found in Imerina. 



NO. II 76, VOL. 46] 



The watershed of the island lies much nearer the east coast 

 than the west, and the two chief rivers rising in the extreme 

 east traverse the breadth of the province on their way to the 

 Mozambique Channel. The Ikopa, fed by the Sisaony, the 

 Andromba, the Mamba, and other stream*, flows north-westward 

 through the fertile plain of Betsimil^taira, and farther north is 

 joined by the Betsiboka, under which name the united stream 

 runs on to the sea at the Bay of BembatcSka. Lake Ilasy is 

 the only large body of water in Imerina, and probably owes its 

 origin to volcanic subsidence. 



On account of its altitude Imerina ha> a pleasant temperate 

 climate, although lying within the tropics. The south-east trade- 

 winds, blowing fresh and moist over the forest belt and the 

 wooded plains of the east, make the atmosphere peculiarly 

 bracing in the cooler season. The annual rainfall at Antana- 

 narivo is about 53 inches. Through the clear pure air distant 

 landscapes stand out with remarkahle sharpness of outline. 

 Towards sunset Imerina is seen in its most attractive aspect y 

 the hills, range beyond range, assume the richest shades of 

 purple, the sky flames with crimson and gold, and the long clay 

 walls of the native compounds glow like streaks of vermilion. 



The general aspect of the province is bare, except for patches 

 of primaeval forest in the northern districts. Moor-like hills, 

 which would look utterly dreary but for the marvellous atmo- 

 spheric effects, predominate. Near Antananarivo the dried- up bed 

 of an ancient lake, known as Betsimitatatra, forms a great plain, 

 covered with rice-fields, which support a dense population. The 

 steep sides of the river valleys are terraced, like great green stair- 

 cases, with rice-plots, where the grain is sown broadcast, and 

 whence the young plants are transplanted in the larger fields 

 along the river-plains and in the meadows left by dried-up 

 lakes. 



The political subdivisions of Imerina are mainly tribal, and 

 are used for purposes of taxation, and for the apportionment of 

 military levies and forced labour. No census has been taken, 

 but an estimate based on the number of villages and houses 

 justifies the estimate of the population at about 1,100,000. 

 Except Antananarivo, there are only small villages in the pro- 

 vince, but these are clustered very closely together, especially to 

 the north and north-west of the capital. Several of these were 

 formerly tribal capitals, and Ambohimanga still retains nominal 

 equality with Antananarivo in royal speeches. The old 

 I villages were always built on hills for purposes of defence, and 

 surrounded by double or treble lines of fosses and embankments 

 dug out of the hard red clay. A narrow bridge of the red clay 

 leads to the gateway, which is formed of blocks of rock, either a 

 circular slab 10 or 12 feet in diameter, which was rolled between 

 upright gate-posts so as to block the way, or massive upright 

 monoliths bearing strong wooden gates. In recent times the 

 Hovas have largely deserted these fortresses, and built them- 

 selves villages close to the rice-fields. Graves of the aboriginal 

 Vazimba are scattered over the province, but local feeling 

 prevents any examination of these from being made. 



SOCIETIES AND ACADEMIES. 



Paris. 

 Academy of Sciences, May 2. — M. d'Abbadie in the 

 chair. — The movements of minute organisms analyzed by means 

 ofchronophotography, by M. Marey. Using an arrangement 

 described in the Revue Ghurale des Sciences in November last, and 

 in Nature, vol. xlv. p. 228, M. Marey has obtained photo- 

 graphs of the movements of blood corpuscles in the capillaries, 

 and has analyzed the movements of zoosphores in the cells of a 

 Cladophora. Enlargements from these negatives have been 

 presented to the Academy. By taking a series of pictures at 

 intervals of about one-tenth of a second, and projecting them 

 upon a screen at about the same rate, the effect of the real 

 motions of the object can be reproduced. The arrangement for 

 doing this will be described in a future communication. — Ob- 

 servations of Swift's, Denning's, and Winnecke's comets, made 

 at Algiers Observatory with the cotidL equatorial, by MM. 

 Rambaud and Sy. Observations of position are given.— On the 

 approximation of functions of very large numbers, by M. Maurice 

 Hamy. — On the tautochronism in a material system, by M. Paul 

 Appell.— On the laws of electrolysis, by M. A. Chassy. When 

 a substance having the formula M^R, is electrolyzed, M desig- 

 nating an electro-positive and R an electro-negative radicle, one 

 equivalent of the radicle R, and t equivalents of the radicle M 



