'■5 2 



NA TURE 



[January 15, 1903 



In ihe ihird part of the Beilrage zur Psychologie nnd Phil- 

 ,ou>phie, Dr. Gotz Martius gives a detailed investigation on the 

 •duration of light sensations. It is pointed out that "Talbot's 

 Liw,'' while defining the limits within which intermittent 

 sources of light give rise to a uniform light-sensation of mean 

 intensity, gives no information as to the actual duration of the 

 light-sensation itself. Dr. Martius, after describing an ap- 

 paratus used by Prof. Exner, gives an account by Karl 

 Minnemann of a new light interrupter. It appears that the 

 time which elapses before the sensation is a maximum depends 

 on the intensity of the stimulus, decreasing in general as the in- 

 tensity increases, while the duration of the sensation depends 

 both on the intensity and on the duration of the stimulus. A 

 discussion of the bearing of the actual results on kindred 

 investigations such as those of Charpentier and Shelford Bidwell 

 •is noteworthy. 



A somewhat remarkable attempt to trace points in common 

 "between such apparently different subjects as biology and educa- 

 tion is made by Prof. Leopoldo Maggi, writing in the Lombardy 

 Rendiconli in a paper entitled " Tachygenesis and University 

 Studies." Both in the vegetable and animal kingdoms, it is 

 pointed out that in the transition from the lower to the higher 

 forms there is a continuous acceleration in the development of 

 maturity, and this law of embryonic acceleration, which, follow- 

 ing E. Perrier, the author describes as Tachygenesis, is an inevit- 

 able consequence of the struggle for existence. The same laws 

 may be applied to social life, and it is suggested that they tend 

 to bring about a reduction of the time given to university study 

 in the lifetime of a man, but against this tendency there is the at 

 present insuperable barrier opposed by regulations which fix 

 the number of years required to complete the university courses. 

 The new university regulations in Italy have reduced the 

 minimum number of lectures in any course from about seventy 

 <o fifty, and this the author considers a good reason for reducing 

 the length of the qualifying period for the university degrees. 

 Prof. Maggi suggests several other applications of biological 

 principles to allied social problems. 



An interesting article on the transmission of vision to a dis- 

 tance by electricity is contributed by Lieut. J. H. Cobl)n to 

 L' Eclairagc Electrique for December 27. The author reviews 

 briefly the theoretical aspect of the subject and the attempts 

 which have been made at its practical solution. He suggests that 

 some less sluggish transmitter than a selenium cell may have 

 to be sought before satisfactory results are obtained, and as re- 

 ceiver proposes the use of a Blondel oscillograph, the moving 

 part consisting of a tube which, as it is deflected, cuts off more 

 or less of the light from a source of constant intensity. This is 

 a modification of the method of Ayrton and Perry ; another 

 method proposed by M. Weiller is to use a sensitive flame the 

 intensity of which is varied by a telephone diaphragm actuated 

 by the transmitted current. In addition to the problem of re- 

 producing the intensity of the illumination, a satisfactory solution 

 has to be found to the difficulty of exploiing the object and image 

 -synchronously at transmitting and receiving stations as the 

 whole surface has to be covered in less than one-tenth of a 

 second, the time of duration of the retinal impression. The 

 author concludes that the problem is still surrounded with great 

 •difficulties. 



Symons's Meteorological Magazine for December last contains 

 a climatologicat table for the British Empire for 1901, so far as 

 it can be shown by nineteen representative stations, but it is not 

 claimed that the records quoted furnish more than a few useful 

 samples of the various climates included in the British 

 ■dominions. The highest temperature in the shade was 110° at 

 Adelaide, in February. A new station has been included, viz. 



NO. 1733, VOL. 67] 



Dawson, where a temperature of - 50° in the shade was re- 

 corded in December, but the observations are incomplete. The 

 highest mean temperature was 82°'i at Colombo, and the lowest 

 36° '4 at Winnipeg. The driest station was Adelaide, mean 

 humidity 59°, and the dampest Colombo, mean humidity 82°. 

 The highest temperature in the sun was 168°, at Trinidad. The 

 greatest rainfall was 1 14 inches, at Lagos, and the least 

 18 inches, at Adelaide. ' None of the extremes referred to can 

 claim distinction as " records,'' but at individual stations the 

 sun temperatures at London, 139° '8, and at Malta, l62°'9, are 

 the highest observed there, and at London the number of rainy 

 days, 128, is the lowest since these interesting tables were 

 commenced. 



The latest issues of the Bulletin of the Entomological 

 Division of the U.S. Department of Agriculture include the 

 Proceedings of the fourteenth annual meeting of the Association 

 of Economic Entomologists and some miscellaneous results of 

 the work of the division. In the former, attention is called to 

 the magnitude of the injuries inflicted by insects on the forests 

 and forest-products of the United States, and the crude con- 

 dition of our knowledge relating to the life-history of the insects 

 in question. It is urged, therefore, that the work of the division 

 is one of great and increasing importance. 



The first part of vol. vii. of the Anales of the National 

 .Museum of Buenos Aires contains a memoir, with portrait, of 

 the late Dr. C. Berg by Sefior A. Gallardo. In the same issue, 

 Seiior A. Mercerat describes a very imperfect skull of a toxodont 

 from the pampean formation of Azul, which is regarded as 

 representing a new genus and species, under the name of 

 Caroiibergia azulensis. 



We have received from the director, Captain S. S. Flower, a 

 copy of a handy little guide (with plan) to the Zoological Gar- 

 dens at Giza, near Cairo. The general introduction is written 

 in English, French and German, and the names of the animals 

 are given in several languages. The issue of this guide may be 

 taken as an indication that the institution under Captain 

 Flower's charge is in a satisfactory and progressive condition. 



The latest issue, vol. lxxiii. part i. , of the Zeitschrift fur 

 wissenschaftliche Zoologie contains three papers, all of a highly 

 technical nature. In the first, Herr Max Abel treats of re- 

 generation among the oligochietous worms ; in the second, 

 Herr J. Miiller discusses our knowledge of the land planarians 

 of the family Bipaliidre ; while in the third, Herr K. Hann 

 describes the development of the common hydromedusan Clava 

 squamata. 



In the December number of the Zoologist, Mr. F. Coburn 

 describes and figures a specimen of the British wild goose named 

 Anser paludosus by Strickland in 1858. The type of that form 

 has been generally regarded as an old male of the bean-goose 

 {A. segetum) ; but a specimen obtained in 1896 by him at St. 

 Abb's Head, Scotland, leads Mr. Coburn to conclude that it is 

 a perfectly valid species, characterised by its large size, long 

 neck and large (eet, as well as by its aquatic habits. Apparently 

 the bird was well known to the Yorkshire "carr-men" and 

 " marsh-men " half a century ago, but no examples are known 

 to science save the type and the one procured by Mr. Coburn. 

 Where can be the habitat of this apparently distinct species is 

 now the question. 



The first three parts of the second volume of the Records of 

 the Botanical Survey of India have been issued. Mr. J. J. 

 Wood has compiled a list of plants mainly from the province 

 of Chutia Nagpur. This part includes a map of the district and 

 two sectional diagrams. Mr. Gammie has recorded the results 

 of his investigations into plants used during periods of drought. 

 For the purpose of making bread, seeds of species of Indigofera, 



