Feb. lo, 1888.] 



SCIENTIFIC NEWS. 



135 



Short studies from Nature. By various Authors. Illus- 

 trated. London, Paris, New York, and Melbourne : 

 Cassell and Co., Limited. 



We have here ten " short studies " by different writers, 

 but it does not appear who has selected either the sub- 

 jects or the authors. Mr. W. S. Dallas, F.L.S., discourses 

 in a very interesting manner on bats. These animals, it 

 is remarked, like their companions the owls, are looked 

 upon by the general public as uncanny and of evil omen. 

 '■ Angels of all kinds," we read, " are represented with 

 birds' wings, while those of bats have, by universal con- 

 sent, always been conferred upon demons." It has, of 

 course, been repeatedly pointed out that, to represent any 

 being supposed to be formed on the human type with 

 wings of any kind attached behind the shoulders is a 

 blunder painful to the eyes of the naturalist. 



In their diet bats vary. Some of them, like those of 

 Britain, prey chiefly upon night-flying insects, and are 

 therefore to be welcomed by everyone save the ento- 

 mologist. But in the Eastern Archipelago, in Australia 

 and South America there are fruit-eating bats, which 

 occasion serious damage in orchards and vineyards, the 

 more as they are endowed with an insatiable appetite. 

 A specimen of the small Indian bat, Cynopterus mar- 

 ginatiis, has been known to eat in three hours double its 

 own weight of fruit. 



A structural peculiarity of the bats appears in the naked 

 membranes about the ears and nose, which seem to be 

 exquisitely sensitive organs of feeling. These appendages 

 are the more highly developed in bats the more decidedly 

 nocturnal are their habits and the darker the retreats 

 which they frequent. 



It is an interesting question why the prevailing colours 

 of the bat tribe should be so sombre. Insects which fly 

 in the twilight are often very richly coloured. 



Another moot point is why the so-called " vampire " 

 bats should be so greedy for blood. It is evidently not 

 necessary to their existence, and it is highly probable 

 that the ancestors of many can never have had the 

 opportunity of such a feast. Whence, then, this strange 

 craving ? 



Passing over an essay on " Flame," by Prof. F. R. 

 Eaton Lowe, we find Dr. R. Brown, F.L.S., describing 

 the migrations of birds. This author reminds us that the 

 " mysterious unerring instinct " ascribed to these creatures 

 by the naturalists of the past, and by not a few " unnatura- 

 lists " in the present, is a delusion. The vast mortality 

 incurred on these half-yearly journeys proves that the 

 instinct is very erring. Birds do not take a straight line 

 to their destination, but follow rivers, coasts, valleys, etc. 

 We have, however, to deal with the great difficulty that 

 a part of the birds of some species in a given country 

 will migrate while their fellows remain. The robin is 

 migratory in some parts of Germany, but stationary in 

 Britain. It is also mentioned as a curious fact that the 

 nightingale, though not uncommon in the Valley of the 

 Thames, eschews the milder climate of the Channel 

 Islands, West Devon, and South Wales. 



Mr. G. C. Chisholm, B.Sc, treats on " Snow." He 

 enlarges on the use of snow as a protection against 

 extreme cold, but he overlooks the fact that it robs the 

 earth of heat in several ways. When watery vapour is 

 turned into snow in the upper regions of the atmosphere, 

 the latent heat of each particle is set free and escapes 

 into space. So long as snow lies the rays of the sun are 



radiated oif, and, as far as this world is concerned, go to 

 waste. And when the snow melts, a vast quantity of 

 heat is rendered latent. It is very possible that were it 

 not for snow in some region from which the winds arrive 

 plants would need no protection. 



" Dragon Flies," by Mr. W. S. Dallas, is a pleasing 

 and instructive paper. The author exposes the vulgar 

 errors involved in such synonyms as " horse-stingers " 

 and " devil's darning needles." But we fear he will 

 plead in vain on behalf of these insects, which injure 

 neither our persons nor our crops, and which aid the 

 swallows in ridding the air of flies and gnats. 



Passing over, from lack of space, the papers on " Oak- 

 apples " and " Comets," we meet with an account ot 

 " Caves," by Mr. James Dallas, curator of the Exeter 

 Museum. Here we are compelled to notice certain errors 

 in point of locality. Fingal's Cave is in the Isle ot 

 Staffa, and not "off the coast of Ireland." Kinderscout, 

 with its gritstone cavern, is not in Yorkshire, but in 

 Derbyshire, being, in fact, the highest summit of " The 

 Peak." There is a good illustration of the grotto ot 

 Antiparos, but we find no mention of it in the text. 



" The Glow Worm," by Mr. G. G. Chisholm, in- 

 cludes a notice of other phosphorescent animals, terres- 

 trial and oceanic. Among the former, the lantern-fly ot 

 Guiana {Fidgora laternarid) and the candle-fly of China 

 (Fidgora candelaria) still remain doubtful. 



The concluding memoir on " Minute Organisms," by 

 Mr. F. P. Balknill, treats not of bacteria and micrococci, as 

 might perhaps have been expected, but of the Fora- 

 minifera. 



We must pronounce the joint production of the authors 

 before us a very readable and a highly-instructive book, 

 attributes which we do not always find in combination. 



An Elementary Treatise on Light and Heat. By the Rev. 

 F. W. Aveling, M.A., B.Sc. (London : Relfe Bros. 

 1887. 3s. 6d.) 

 Mr. Aveling seems to have yielded to one of the chief 

 educational temptations of the day, and added yet another 

 to the many books offering a short cut, not to knowledge, 

 but to such an evanescent imitation of knowledge as 

 may tide a candidate over an examination, and leave him 

 after it very little better than before. If a book like 

 this were made for himself by a student, while experi- 

 menting and reading, or if it were used only as an 

 accompaniment to experimental work and fuller reading, 

 there would be great advantage to him in having such a 

 clear epitome of his work as is given by Mr. Aveling ; 

 but unfortunately it is so much easier to " get up " the 

 subject from the epitome, and human nature tends so 

 decidedly in the direction of least resistance, that it has 

 become a duty on the part of authors and teachers to 

 refrain, as far as may be, from providing such oppor- 

 tunities. For examinational purposes, Mr. Aveling's 

 book may be highly recommended ; for purposes of real 

 education it is little likely to be used. 



The Morphology of the Carinae upon the Septa of Rugose 

 Corals. By Mary E. Holmes, A.M Boston : Bradlee 

 Whidden. 



This memoir, which has been accepted as a thesis for 

 the degree of Doctor of Philosophy by the University of 

 Michigan, is the outcome of thoroughgoing scientific 

 work. The authoress has, however, selected a subject 

 which lies quite outside the region of popular interest, 

 and which can scarcely be made intelligible save to spe- 



