490 



NATURE 



February 21, iqi8 



sula on the Red Sea coast, near lat. 21° N. The 

 species in question is doubtless O. capense, Schlecht., 

 which has already been recorded by Prantl as having 

 been collected by Schweinfurth in May, 1864, in an 

 adjacent locality — the western side of Macaur Island, 

 Jat. 21° N., on coral detritus. This species, unlike the 

 European O. vulgatum, Linn., prefers dry situations. 

 It was collected by Schimper in Abyssinia in sandy 

 desert. The late Prof. Pearson met with it among 

 Acacia scrub in German South-West Africa, and in 

 deep sand at Kiubis, in Great Namaqualand. In Natal 

 it has been found growing only on very dry sandy 

 knolls near Durban. Mr. Crossland remarks that two 

 showers in November constitute all the rain that had 

 fallen at Dongonab during 1917, and that wholly dry 

 years are common. The desert flora of lat. 21° N. is 

 much less abundant, and individual plants are more 

 stunted, than is the case only a hundred miles further 

 south. Generally the plants that occur are confined to 

 water-courses and drainage lines, but the cliff on which 

 he met with the Ophioglossum bears a few bushes near 

 the top. 



We have received the 1916-17 part of the Transactions 

 and Proceedings of the Perthshire Society of Natural 

 Science, the pages of which show a. continuance of 

 careful work. Mr. Henry Coates, the curator of the 

 admirable regional museum, deals with some stone 

 cists from the Carse of Gowrie ; Mr. Graham Callander 

 has an interesting paoer on methods of archaeological 

 research; Mr. J. A. Donald discusses to good purpose 

 some of the difficult problems of afforestation ; Mr. 

 D. A. Haggart describes, in a racy manner, various 

 faunistic and floristic rambles in Mid-Perth, especially 

 among the hills. One of Mr. Haggart's notes is en- 

 thusiastic over the delicious meal which may be made 

 of roast sparrow, and another directs attention to a 

 change of colour exhibited by the beetle, Carabus 

 catenulatus, when it is excited. Mr. Barclay, the presi- 

 dent of the society, records some interesting botanical 

 rarities, such as PoLamogeton gracilis (reputed to be 

 a hybrid of P. alpinus and P. heterophylltis), which 

 differs from all, or almost all, other pond-weed hybrids 

 in being fertile and producing good fruit. It has 

 hitherto been found in Britain in only one station in 

 the Shetland Islands. The Proceedings contain a num- 

 ber of notes of interest, e.g. on the activity of a hedge- 

 hog in catching bees flying and crawling about in front 

 of a hive, and on the sub-fossil antler of an elk (Alces 

 machlis) found near Methven in 1801. It measured 

 27 in. across from one extreme snag to another, and 

 weighed 8J lb. A good photograph is given. The 

 Perthshire Society was founded in 1867, and it deserves 

 to be congratulated on its record of fifty years of 

 activity. It wears well, and is a fine example of what 

 a local Naturar History Society should be." 



In an article on "Forestry in the Dominion of New 

 Zealand," just published in the Quarterly Journal of 

 Forestry (vol. xii., pp. 1-28), Sir W. Schlich gives an 

 account of the present condition of the forests in that 

 country, and critically discusses their future manage- 

 ment. A Royal Commission, which submitted a re- 

 port to the Government in May, 1913, practically re- 

 commended that the valuable native forests should be 

 replaced by artificial plantations of exotic trees. Sir 

 W. Schlich considers it injudicious to neglect the 

 natural forests, and urges that a considerable area of 

 these should be declared permanent State reserves, and 

 managed for the sustained production of timber in 

 such a way that the more valuable species would 

 naturally regenerate themselves. It is a melancholy 

 fact that, apart from a few remnants, the Kauri forests 

 have been destroyed. This wonderful tree yields one 

 of the finest coniferous timbers in the world, and surely 

 NO. 2521, VOL. 100] 



something might be done to restore the tree beyond 

 the reservation of a few acres for sentimental reason^. 

 It is asserted by the Royal Commission that "the 

 timber trees of New Zealand are of much slower 

 growth than those grown in forestry operations the 

 world over." This opinion is quite unfounded. Mr. 

 D. E. Hutchins, who has lately been in New Zealand, 

 states that Kauri is fit to cut at 100 years old, and is 

 then 2 ft. in diameter, which is a greater rate of 

 growth than that of most European trees. Sir W. 

 Schlich, using the meagre statistics available, holds 

 that the growth of Podocarpus Totara, the second most 

 valuable native conifer, is equal to that of silver fir, 

 which produces the largest yield of timber of any tree 

 on the continent of Europe. The article, which is 

 replete with statistical, economic, and geographical 

 information, is illustrated with four maps of New 

 Zealand, showing the distribution of the forests, rain- 

 fall, and physical features. 



Messrs. R. D. Salisbury and G. N. Knapp, in "The 

 Quaternary Formations of Southern New Jersey" (Final 

 Report of State Geologist, vol. viii., 1917), illustrate 

 by an admirable series of drawings the stages in the 

 history of the coastal plain, the material of which is 

 largely derived from Glacial outwash, and was accumu- 

 lated under terrestrial conditions. A former diversion 

 of the Hudson River is suggested. 



The Geological Survey of Scotland has issued a 

 memoir on "The Economic Geology of the Central 

 Coalfield of Scotland, Area II." (1917), covering the 

 country round Falkirk. A number of vertical sections 

 are conveniently included in a pocket at the end. We 

 notice how the miners' words, "fakes," "blaes," and 

 " ribs," which have also invaded Irish geology from the 

 north, are accepted as technical terms, for the benefit 

 of those who will primarily use the memoir. 



The Canadian Department of Mines has issued a 

 recent memoir descriptive of the magnesite deposits of 

 Grenville District, Quebec. Magnesite is a refractory 

 material, extensively used in connection with the manu- 

 facture of open-hearth steel, and the British demand 

 has been, in the past supplied mainly from Greece, 

 particularly from the island of Euboea, which furnishes 

 the mineral in a high state of purity, containing about 

 46 per cent, of magnesia, a little more than i per cent, 

 of lime, and less than i per cent, of silica. It is of great 

 importance that we should be able to obtain all the 

 materials required for our basal industries from within 

 the British Empire, and hence authoritative informa- 

 tion upon these Canadian deposits is verv welcome. 

 The Grenville area lies just to the north of the River 

 Ottawa, about midway between the towns of Ottawa 

 and Montreal, and is thus conveniently situated as 

 regards exportation of its mineral production. A con- 

 siderable number of separate deposits have already 

 been proved to exist; the magnesite is practically every- 

 where intimately associated with dolomite, so that 

 most of it contains more than 7 per cent, of lime. 

 The quantity of magnesite already proved containing 

 less than 12 per cent, of lime is estimated at close 

 upon 700,000 tons, whilst nearly .t;oo,ooo tons of mixed 

 magnesite and dolomite, containing more than 12 per 

 cent, of lime, are also known to exist, and there is 

 evidence that other deposits of magnesite still remain 

 to be discovered. It is important that the attention 

 of ironmasters in this country should be directed to the 

 existence of a new source of supply of this important 

 material. 



In the Philosophical Magazine for January Dr. J. G. 

 Eeathem discusses the motion of a hydrodynamical 

 liquid past a two-dimensional contained solid having a 



