372 



NA TURE 



[Atigust 14, 1879 



gascar M. Grandidier discovered the fossil remains of a 

 hippopotamus (a pachyderm not now living in the island), 

 of gigantic tortoises (which are now only found in the little 

 island of Aldebra to the north of Madagascar), and of the 

 probably very recently extinct struthious bird, the JEpyor- 

 nis maximi(s,\]\ioiQ egg (i2jin. xgilin.) so far exceeds that 

 of any other known bird. It seems highly probable, there- 

 fore, that a systematic examination of these less elevated 

 portions of Madagascar would reveal the existence of 

 much that is interesting both in palaeontology and geo- 

 logy, and so light would be thrown upon many problems 

 connected with the anomalous animal life of the country 

 and of the neighbouring islands in the Indian Ocean. 

 It is evident that these maritime plains were under water 

 during portions at least of the Secondary period, at which 

 epoch the high granitic region alone formed the Island of 

 Madagascar, then a country probably only a third of its 

 present extent. 



Dr. Auguste Vinson speaks of seeing yellow sandstone 

 on the eastern coast, and he also describes the plain 

 between the two eastern lines of forest as being composed 

 of beds of sedimentary formations, "rich in fossil re- 

 mains." Unfortunately he gives no particulars as to these 

 alleged extinct organisms, so we are still in the dark as to 

 the geological age of these formations. In sailing down 

 the river B^tsiboka to the north-west coast, I noticed at 

 one point that for a considerable distance the river bank 

 was formed by layers of yellowish sandstone closely re- 

 sembling a low wall of masonry. Some of the courses 

 appeared much weathered, while others had a smooth 

 face as if of much harder materials. 



From the account given by an intelligent native of 

 some rocks in the western part of Madagascar, and a 

 little to the south of the centre, a conglomerate seems to 

 be found there, for he describes hard rocks of great size 

 as being filled as thickly as possible with rolled pebbles of 

 all dimensions and shapes. He also mentions that near 

 the sea he found a hard black stone which rang like iron, 

 and was full of shells in good preservation and appearance. 

 Unfortunatelyhetoobrought no specimens forexamination. 



A little more information as to the geology of Mada- 

 gascar is found in papers contributed to scientific perio- 

 dicals in England and France several years ago. The 

 earliest of these is by the late Dr. Buckland, who, in a 

 " Notice on the Geological Structure of a Part of the 

 Island of Madagascar" ' (Port Louquez, near the northern 

 extremity), describes a sandstone without fossils, which he 

 compares to the New Red Sandstone, and in which are 

 intercalated trap-rocks similar to those of Antrim in 

 Ireland. 



As to the north-west side of Madagascar, in the An- 

 nales des Mines (1854, Sme srfrie, t. vi. pp. 570-576) there. 

 is a paper on the discovery of beds of lignite both in 

 the island of Nosibd and at two points on the north-west 

 coast. In the opinion of the officers who made the ex- 

 ploration the beds of this combustible are more ancient 

 than the Tertiary formation. It is contained in layers 

 of sandstone and clay schists, is fibrous, and shining, 

 and burns readily with a long and white flame, leaving 

 little ash. If beds of this lignite should be discovered in 

 greater thickness it will therefore be valuable both as 

 steam coal and for use in the industrial arts. 



In the same French publication of a little later date 

 (5me sdrie, t. viii., 1856) there is an "Essai surla G&logie 

 de Nosibd," in which the soil of that island is described 

 as consisting of three different groups of strata ; — (i) 

 granitic rock, gneiss, mica-schist, slaty-schist, and 

 plastic clay ; (2) red and yellow sandstones, traversed by 

 veins of gneiss and quartz ; while (3) is essentially vol- 

 canic, consisting of basaltic and trap lavas, overlaid in 

 some places by beds of sandy material, tuffs, and volcanic 

 rapptiis. The essay is accompanied by a complete 

 geological map. 



* Trans. Geol. Soc. London, vol. v. p. 478. 



Since the date of this last paper some further attention 

 has been paid to this part of the country in connection 

 with the French Company proposed by M. Lambert,' but 

 hardly anything more has been done towards a scientific 

 examination of other portions of Madagascar except a 

 slight notice of the peninsula inclosing Antongil Bay,^ 

 although probably .M. Grandidier will have some fresh 

 information in his great work now in progress. 



It may be here observed that a reef barrier of coral 

 extends for at least 350 miles along the east coast, varying 

 in its distance from the land from a quarter of a mile to 

 three or four miles ; while fringing reefs surround the 

 northern end of the island, extending for 400 miles down 

 its eastern side, and are also found on the south-west 

 coast. 



With regard to minerals, Madagascar is tolerably rich 

 in some of the most useful metals. Iron is found in great 

 abundance in Imdrina, sometimes almost in a pure state. 

 In some of the hills it is so plentiful that it is difficult to get 

 a bearing with the compass, from the deflection caused by 

 the iron in the ground. Copper, lead, and silver have also 

 been discovered, and from the geological structure of the 

 country it is highly probable that gold would be found in 

 some of the ravines of the granitic highlands ; but as it is 

 at present a serious offence against the native laws to 

 search for the precious metals, hardly anything has been 

 done in this direction. Rock-salt is found near the coast, 

 and nitre is also met with. Iron pyrites, from whicli 

 sulphur is extracted, is also found in abundance ; in the 

 northern part of the island antimony seems to be plentiful, 

 and oxide of manganese has been found about fifty miles 

 south of the capital. A substance resembling plumbago 

 exists in great abundance, and is used by the Malagasy 

 to colour and glaze some of their articles of pottery. A 

 considerable variety of ochres and coloured earths are met 

 with, and are used not only for colouring the native 

 houses, but also in dyeing some of the woven cloths made 

 by the people. 



In conclusion, it may be remarked that there is a vast 

 extent of country on the coast-plains where the soil is 

 most fertile, but which is only thinly peopled, or has no 

 population at all. Many parts of the island whicli 

 separate the territory of one tribe from another are well 

 watered and wooded, and seem to invite occupation. 

 Madagascar could well sustain a population from ten to 

 twenty times its present amount, for hardly any portion of 

 it is rainless or desert, except a small section of the 

 extreme south-western coast. Surrounded by the ocean it 

 enjoys an abundant rainfall, so that the droughts which 

 constantly afflict large portions of Southern Africa never 

 occur in Madagascar, while its insular position gives it a 

 more equable climate, freer from extremes of temperature, 

 than is enjoyed in most tropical countries. 



James Sibree, Jun. 



NOTES 



The first zoological station established in Scotland was 

 opened the other day at Cowie, near Stonehaven. The work, 

 which is more directly in connection with the natural history 

 class of the Aberdeen University, will be carried on in a small 

 wooden house which was erected in the beginning of last week 

 on flat ground, a few yards to the north of Cowie, and close to 

 the sea-shore. The building was constructed in sections, special 

 provision being made for ventilation. It consists of two apart- 

 ments, the lesser of which is to be fitted up as a library and 

 office, while the main room will be devoted to reception of the 

 proceeds of the dredging, trawling, and otlier expeditions. The 

 latter department contains the dredging and trawling apparatus, 

 a number of microscopes, with chemical and other appliances 



' See Afma/es des Mines, 6me s^rie, t. x. pp. 277-319. 

 = Bull, de la Soc. de Cdog., Sept. et Oct., 1867. 



