20 



NATURE 



[May 2, 1 901 



tons. Mr. Wethered suggests that another Commission should 

 be appointed to consider the probable duration of the coalfields. 

 Another point on which information is required is as to what 

 natural stores of coal are under the Secondary rocks, and at 

 what depths. It is of national importance that this information 

 should be obtained. 



Symoiiss Meteorological Maqaiiiie for April contains what 

 purports to be the first tables of the climate of Pemba ever 

 published. They were taken by Mr. T. Burttat Banani, during 

 the years 1899 and 1900. The small island of Pemba forms, 

 with Zanzibar, that portion of the British East Africa Pro- 

 tectorate nominally under the rule of the Sultan of Zanzibar, 

 the position of Banani being approximately 5^ 15' S., 39' 43' E. 

 The temperature is of course very uniform, the mean of the 

 monthly maxima being 83° '4 and of the minima 70° "8, the 

 absolute maximum being 95° and the minimum 65'. The rain- 

 fall is copious, averaging about 98 inches. The two rainy 

 seasons are well marked, the greater being March to May, and 

 the less November to January. 



Mr. G. W. K1RKAI.DY has favoured us with a copy of his 

 paper on the stridulating organs of water-bugs, recently pub- 

 lished in ihe /oiirna/ of the Quekett Microscopical Club. The 

 males of these insects, which alone produce the sounds, can 

 mostly be referred to their proper species from the stridulating 

 organs alone. Generally it seems that the sound is produced by 

 drawing the comb-like structure situated on the tarsus of one leg 

 across the femur of the other, and vne versa. But it is believed 

 that there is also a second musical area, one of the constituents, 

 at least, of which is situated on the abdomen. Observations are 

 needed as to the precise modus operandi of both types of 

 stridulating organs in these insects. 



The Biologisches Centralblatt of April i contains the two 

 concluding sections of Dr. C. Rengel's account of the life- 

 history of the great black water-beetle commonly known as 

 Hydrophilus piceus. It is shown that, unlike those of the brown 

 water-beetles (Dylisais), which devour free-swimming creatures 

 like tadpoles and the larva; of other insects, the larva; of the black 

 water-beetle subsists on slow-moving organisms, especially pond- 

 snails. In the earlier stages of their existence the larv.e devote 

 their attention to Physa and the smaller kinds of Lymnn;a, but 

 when full grown they do not hesitate to attack the comparatively 

 large Plaiiorbis (orneiis. The idea that these larva." always seek 

 a hole in the ground in which to pupate is shown to be incorrect, 

 the transformation having been observed to take place among a 

 mass of weeds. It seems also that when a hole is selected, this 

 is not excavated by the Iarv;v themselves. By an inadvertence 

 the title of this paper occurs in the table of contents of the 

 Centralblatt of April 1 5. 



The issue of the Revue Scientifiqtie of April 20 contains 

 the first instalment of an interesting article by M. Henri Coupin 

 on the song of birds. The author commences by referring to 

 the large proportion of tuneful species met with among the 

 birds of Europe, which he sets at ten per cent., whereas in the 

 tropics it falls as low as one per thousand. The gorgeous birds 

 of the tropics he compares to actresses without talent, who 

 depend for success on the richness of their toilets. Stress is 

 then laid on the fact that, in spite of its simplicity, bird-song 

 cannot be imitated by any known musical instruments. It is 

 possible, indeed, to reproduce the pitch and intensity of the 

 notes, but not the timbre, which includes such a multitude of 

 .sounds as to defy imitation. Indeed, the observations of M. F. 

 l.escuyer have shown that although the notes of birds corre- 

 spond to those of our musical scale, yet they also include a 

 number of vibrations occupying the intervals between our notes, 

 and it is this which renders imitation impossible. In most birds 

 NO. 1644, VtJL. 64 J 



the duration of the song is very brief; in the thrush and the 

 chaffinch it lasts only two or three seconds, in the blackcap from 

 four to five seconds, and from two to five minutes in the lark. 

 The author then proceeds to analyse the sounds constituting the 

 songs of birds, and to distinguish between their songs .and their 

 alarm-cries. 



We have just received Part vii. ot the bibliography of the 

 more important contributions to American economic entomology, 

 issued by the U.S. Department of Agriculture (Division of 

 Entomology), extending from December 31, 1S96, to January i, 

 1900. This part, prepared under the direction of Prof. L. O. 

 Howard, the entomologist, by his assistant, Mr. Nathan Banks, 

 contains an alphabetical index, under authors' names, of 1383 

 papers in different American ■ periodicals, and a subject-index 

 extending to thirteen pages (double columns) in small type. 

 The book is a good illustration of the energy with which 

 economic entomology is pursued in the United States, where, 

 however, it must be remembered that insects are much more • 

 numerous and destructive than in Europe, or at least in England. 



The issue of Die Umschau for April 20 contains a short 

 illustrated article on the ship Gauss, which has been built for 

 the German Antarctic Expedition. A photograph from a model 

 and some views of the vessel in various stages of construction 

 are reproduced. 



Dr. E. Friedrich contributes a paper on the india-rubber 

 production of Africa to the Deutsche geograpkisehe Blatter. 

 The export statistics of twenty-five African colonies are dealt 

 with, and the results exhibited graphically on a sketch-map, 

 from which some interesting geographical conclusions are 

 drawn. 



The Verhandlungen of the Berlin Gesellschaft fiir Erdkunde 

 contain a brief abstract of a lecture, by Dr. K. Kretschmer, on 

 the physical development of the North Sea coasts during his- 

 toric times'. The author refers specially to the regions near the 

 mouths of the rivers Ems and Jade, and describe^ changes 

 recorded by various authorities since Roman times. 



With reference to Mr. T. W. Kingsmill's letter in last week's 

 issue (p. 60S), Prof. Haddon writes to say that he appreciates 

 its value, but at the same time he wishes to disclaim any first- 

 hand knowledge of Chinese authorities, and to remark that in 

 his article he merely gave an account of M. Ujfah-y's views. 



A vOLtJME on the history of physiology during the sixteenth, 

 seventeenth and eighteenth centuries, by Sir Michael Foster, 

 will shortly be published in the Cambridge University Press 

 Biological Series, edited by Mr. A. E. Shipley. The book will 

 consist of lectures delivered by the author last autumn before 

 the Cooper Medical College in San Francisco. Without claim- 

 ing to be a complete history of the subject the book will contain 

 a full .account of the chief advances made in physiology from the 

 time of Vesalius until the beginning of the nineteenth centur)-. 

 In the same series Prof. Marshall Ward is issuing a work on 

 grasses on a somewhat novel plan. It is essentially a practical 

 book, to be used in the field and in the laboratory, and should 

 be of use, not only to the botanist, but also to the farmer and 

 the gardener. 



We have received from Messrs. A. E. Staley and Co. a 

 catalogue of microscopes manufactured by the well-known 

 Bausch and Lomb Optical Co. of Rochester, New York, U.S.A. 

 From the description of their works contained in the catalogue 

 it is evident that the method of production is essentially 

 American. Machine tools of the most modern description and 

 specialisation of the manufacture of component parts should 

 result in every article being of the highest class. The instru- 

 ments listed of the so-called " Continental " type do not call for 



