664 



NATURE 



[July 22, 1920 



The report is an example of the value of the 

 methodical collection of data. Whether the destruc- 

 tion or control of Glossina, which seemed at first sight 

 an almost hopeless quest, can be achieved by this 

 method we shall no doubt soon learn. 



J. VV. W. S. 



Dante and Trepidation. 



IN a note entitled "La trepidazione in Dante?" 

 (Atti della R. Accad. di Torino, vol. Hi., p. 353) 

 Signor O. Z. Bianco discusses the novel interpretation 

 given by Duhem (" Le Systeme du monde," t. iv., 

 chap. X.) of a well-known passage in the " Paradiso " 

 (xxvii., 142-48) : 



But ere that January pass to spring 

 Through that small hundredth men neglect below, 

 These higher sphere-, shall wiih loud bcUowings ring ; 



The tempest fierce, that seemed to move so slow. 

 Shall whirl the poops where now the prows we see, 

 So thai the fleet shall on iti right course go ; 



Ana following on tue flower, the true fruit be. 



{Flum/tre^s translation.) 



The first two lines clearly allude to the difference 

 between the Julian year and the true value of the 

 tropical year, which Dante assumed equal to i/ioo 

 day, the neglect of which was gradually making the 

 spring equinox occur earlier, and would (if the error 

 were not corrected) eventually make the spring begin 

 in January. Duhem suggested that the second half 

 of the passage alludes to the so-called trepidation of 

 the equinoxes. According to the theory formulated 

 by Tabit ben Korra in the ninth century, the equinoxes 

 do not move uniformly from east to west, but alter- 

 nately advance and recede ip a period of more than 

 four thousand years. This imaginary phenomenon is 

 not alluded to by Al Fargani, from whose text-book 

 Dante seems to have derived his astronomical know- 

 ledge. Signor Bianco rejects Duhem 's suggestion, 

 which is at variance with what Dante says elsewhere 

 (" Convito," ii., 6; " Purgat.," xi., 108) about the slow 

 motion of 1° in a hundred years. It is surely much 

 more natural to suppose that the poet simply meant 

 that long before the spring equinox after some 

 thousands of years had moved back into January, great 

 upheavals would take place in Italy. 



Japanese Botanical Work. 



THE Journal of the College of Science of the 

 Imperial University of Tokyo, vol. xliii., con- 

 tains (article 1) an admirably illustrated, monograph 

 (in English) of the genus of brown seaweeds, Alaria, by 

 Prof. K. Yendo. The author has studied the various 

 species on the west coast of Vancouver Island, along 

 the coast of the Kurile Islands and of Kamtschatka 

 as well as in Japan, and also the material in some of 

 the important European herbaria. The descriptive 

 portion* is preceded by a general account of the 

 morphology, structure, and development. The vexed 

 question of the cryptostomata in the brown seaweeds 

 is discussed at some length, and the author concludes 

 that these tufts of hairs, at any rate in the Lamin- 

 arias, may be regarded as absorptive organs. A 

 rdsumd is also given of the differing views held as to 

 the life-history, especially as to evidence on the 

 manner of renewal of the blades, of Alaria, which, 

 the author considers, "may be either gradual or 

 sudden, according to the conditions of the place where 

 the plant grows." As regards the economic uses of 

 Alaria, though A. esculenta was extensively used for 

 food in earlier times in North-West Europe, and this 

 and other species are still eaten in various sub-Arctic 



NO. 2647, VOL. 105] 



areas, the author concludes that the genus has very 

 little value as human food or for kelp-ash. For 

 manure it may be used equally well with other brown 

 seaweeds. The species inhabit the colder northern 

 seas, the greatest number being found within a range 

 from about 42° N. up to the Arctic Circle. Fifteen 

 species are recognised. Of these full descriptions .ire 

 given, variations in form and synonymy are dis- 

 cussed, and a list of localities is cited. The form 

 and structure of the species are illustrated in nineteen 

 excellent double-page plates. 



The same volume contains a short paper (article 2) 

 by T. Matsushima describing investigations on the 

 transpiration of cut branches, and an ecological study 

 (article 3) by Y. Yoshii of the Ota dunes — both in 

 German. 



In the " Icones Plantarum Formosanarum," 

 vol. viii., Bunzo Hayata continues his descriptive 

 work on the flora of the Island of Formosa, based 

 on the study of the collections of the Botanical Survey 

 of the Government of Formosa. The present volume 

 contains descriptions of species and varieties of 

 flowering plants in various families, and of ferns; 

 III new species and 17 varieties are included. The 

 total number of species of the flora is brought up to 

 3458, contained in 1174 genera representing 169 fami- 

 lies. The genus Citrus (orange, lemon, etc.) is treated 

 at some length, as also are the figs, Ficus, of which 

 the author recognises 29 species in Formosa. In 

 addition to eighty-eight text-figures, the species are 

 illustrated by fifteen excellent full-page plates showing 

 habit and floral dissections., 



Researches on Egyptian Cotton. 



T^ HE newly appointed Cotton Research Board for 

 -*• Egypt has issued a Preliminary Report, in 

 which a sketch is given of the general significance of 

 the Egyptian cotton crop and the formation and pro- 

 posed operations of the new Board are described. 

 Plans of the buildings under construction are shown, 

 and a few illuminating figures serve to bring home 

 to the reader the immense volume of detailed in- 

 formation required in the modern study of crops. An 

 outline of the field of work to be undertaken by a 

 staff of eleven non-Egyptian scientific workers and 

 twenty Egyptians is given for the botanical, entomo- 

 logical, chemical, and physical sides, though the Board 

 is rightly careful not to bind itself to a definite 

 programme. 



Those interested in cotton or in Egypt cannot fail 

 to be very glad that this Board has at last come into 

 existence, but the matter is of wider interest in that 

 a move has here been made towards the separation 

 of administration from research. Both functions have 

 been hampered in the past history of many agricul- 

 tural services by mutual confusion, and we anticipate 

 that the step taken by Egypt in this matter will be 

 generally adopted. 



The only criticism we would offer on this report is 

 upon the reason given for the establishment of the 

 Board, to wit : " Past experience of . . . the dis- 

 advantages attaching to the investigation of cotton 

 problems from the point of view of any one branch 

 of science."' We would rather have judged that 

 Egyptian cotton had been singularly fortunate in the 

 informal and voluntary co-operation of every branch 

 of science, the schools of medicine and engineering, 

 and the departments of survey and geology, as well 

 as the agricultural organisations, having given invalu- 

 able help in all directions. We would suggest that 

 past experience showed rather the need for a body 

 (such as this Cotton Research Board) which would 



