264 



NA TURE 



[July i i, 1901 



Ahhandhingen Dr. Johan Cvijic publishes the second part of his 

 morphological and glacial studies in Bosnia, Herzegovina and 

 Montenegro, dealing with the Karstpoljcn of Herzegovina and 

 West Bosnia. 



In the Transactions of the Edinburgh Geological Society 

 (vol. viii. part i. 1901) Dr. W. Mackie publishes some chemical 

 analyses of Scottish sands and sandstones ranging in age from 

 the Torridon Sandstone to the Blown Sands of Culbin. These 

 analyses show that the proportions of the total alkalis follow 

 fairly closely the results obtained from the proportions of fresh 

 felspar in the several formations. Thus the Torridon Sand- 

 stone, an arkose, which contains fresh felspars, gave an average 

 of 4-61 per cent, of alkali, chiefly potash. Soda is hardly 

 represented. Hence the author doubts if such sandstone could 

 be converted by metamorphism into a gneiss as has been sug- 

 gested. The bearing of his analyses on similar questions is dis- 

 cussed, and he concludes (i) that a silica percentage over 7S, 

 an alumina percentage under 11, and a low percentage of lime 

 and of total alkalis, especially of soda relatively to potash, 

 indicate a sedimentary origin of metamorphic rocks ; and (2) 

 that a silica percentage not above 78, an alumina percentage 

 not under II, a high percentage of total alkalis, &c., indicate 

 origin from an igneous rock. Mr. H. M. Cadell contributes to 

 the same Transactions an important article on the geology of 

 the Oil Shalefields of the Lothians ; and Mr. Herbert Kynaston 

 draws attention to the effects of contact metamorphism round 

 the Cheviot granite. 



The second number of vol. ii. of the West Indian Bulletin 

 has just been issued by the Imperial Agricultural Department. 

 It is devoted wholly to a continuation of the full reports of the 

 papers and discussions at the Agricultural Conference held at 

 Barbados in January last. A great deal of the most useful in- 

 formation is brought together in these pages, the subjects dealt with 

 being of a varied character, and not in all cases strictly agricul- 

 tural. Dr. Alford Nicholls deals with the difficult question of 

 bush fires, which he divides into five classes, approving of some, 

 condemning others. Mr. Watts treats of soils in-" orchard " 

 cultivation, and of pine-apple cultivation in .\ntigua ; Mr. Hart 

 of rubber planting in the islands (illustrated) ; Mr. Sands of 

 the cultivation of onions in .A.ntigua ; Mr. Meaden of breeding 

 for beef in Trinidad, and, with Mr. Hart, of zebu cattle in the 

 same island; and Mr. Whitfield Smith of artificial drying of 

 cacao. Dr. Duerden's instructive communication on the marine 

 resources of the British West Indies, which was some 

 time ago issued as an extra number of the Bulletin, is reproduced 

 in cxtcnso. 



The afforestation of Ireland is advocated by Dr. R. T. 

 Cooper in the Irish Times as a means of increasing the value 

 and productiveness of the country. In Ireland there are about 

 five million acres of unproductive land in a total acreage of 

 20,808,271, every square yard of which could be improved and 

 fertilised by tree cultivation. Yet in all Ireland during the 

 year ending June 1900 only 629 acres were planted with trees, 

 while 145 1 acres were cleared of timber. A serious attempt 

 ought to be made to prevent this destruction of forest and re- 

 cover the immense areas of " bog waste and mountain land ' by 

 a scientific distribution of trees. 



An interesting illustration of the practical importance of the 

 recent discovery that leguminous plants possess the power of 

 utilising the free nitrogen of the atmosphere, and thus increasing 

 the nitrogenous constituents of the soil, is furnished by a pam- 

 phlet on shade in coffee culture, by Mr. O. F. Cook, being 

 Bulletin No. 25 of the U.S. Department of Agriculture 

 (Division of Botany). It seems that coffee growers in Central 

 America, Venezuela and Columbia advocate a certain amount 

 of shade for the cotfee plantations, while those in Brazil and the 

 NO. 1654, VOL. 64] 



East Indies do not. Mr. Cook suggests that the explanation 

 of these contrary results lies in the fact that, while in the first- 

 named countries the shade plants employed are almost exclu- 

 sively leguminous trees and shrubs, in the latter they are 

 chiefly figs, bananas and other non-leguminous plants. Hence 

 the problem is one rather of nutrition than of insolation. A long 

 list is given of the shade plants employed by coffee growers, and 

 the pamphlet is illustrated by a number of photographs. 



Prof. F. Plateau, of Ghent, has recently published several 

 fresh papers, in the Annales de la Socit!te Entomologique de 

 Belgique and the Mc'moires de la Socit'ti Zoologique de France, 

 on the sources of attraction in flowers for insects. His previous 

 conclusion, that insects are but little attracted by bright colours, 

 was confirmed by experiments which showed that brightly 

 coloured stuffs and scintillating metallic objects placed among 

 the leaves had but little attractiveness for insects. With regard 

 to the constancy of insects in visiting the same species of flower 

 only on the same flight, he states that species of Bombus are ■ 

 very inconstant ; Apis mellifica and Anthidiuni inanicatum 

 are, on the other hand, remarkably constant ; species of Mega- 

 chile and Coelioxys less .so. The habit of constancy is 

 attributed to a desire on the part of the insect for a saving of 

 labour. The Syrphidce (hover-flies) show a considerable ten- 

 dency to be attracted by bright colours, whether of flowers or of 

 inanimate objects. To this quality, and not to any aesthetic 

 sense, is to be attributed their habit of hovering over flowers. 



A WEM, illustrated article by Prof. W. M. Wheeler, bearing 

 the title of "Impostors among Animals," presents to the 

 readers of the July number of The Century Magazine 

 some of the leading facts connected with the "mimicry" 

 of animate and inanimate objects by animals, and the 

 consequent adaptation of the latter to their surroundings, 

 in a pleasant and attractive manner. The first illus- 

 tration shows the marvellous- resemblance presented by 

 certain bugs to the rugged bark of the stem on which they 

 dwell, while the second displays the mimicry of orchids by 

 various members of the Orthoptera, which assume a stationary 

 posture with outspread wings on such occasions. Attention is 

 specially drawn to the circumstance that while protectively 

 coloured animals have, as a rule, a simple coloration and 

 quiescent habits — frequently accompanied by the "death- 

 feigning instinct " — those which depend for safety on "warning 

 colours " present the very opposite conditions, being brilliantly 

 and often gaudily coloured, while their habits are calculated to 

 provoke attention and attract observation. 



The current number (vol. Ixx. part iii., No. i) of ihe Journal 

 of the Asiatic Society of Bengal contains several interesting 

 papers on folk customs in India. Captain W. Haig records 

 the origin, the marriage laws, religious observances and funeral 

 rites of the Rangari caste in Barar ; in another paper he does 

 the same for the Velania caste, and in a third communication 

 he narrates the legendary account of Shah Abdur-r-Rahman-i- 

 Ghazi, the warrior saint of Barar. Mr. S. Appadorai gives far 

 too brief a paper on the heroic Codlings in Malabar folklore ; 

 and the riddles current in Bihar are recorded by Mr. S. C. 

 Mitra. In a very interesting paper, illustrated by four plates, 

 the Rev. P. O. Bodding describes a number of polished stone 

 implements found in the Santal Parganas. These, as almost 

 everywhere else, are believed to be thunderbolts. The Santals 

 believe that a house where such a " thunderbolt " is kept is 

 proof against lightning, and, as in the north of Ireland and else- 

 where, they are also supposed to possess remarkable therapeutic 

 power. Water in which a thunderbolt has been rubbed or 

 placed is used, both externally and internally, to cure many 

 ailments. 



