28 



NA rURE 



[May 12, i; 



derived, invent new descriptive terms which seem 

 neither necessary nor advantageous. As showing how 

 difficult it is to quote accurately detailed accounts of an 

 organism of which the writer who quotes has no special 

 knowledge, the following is an instance. MM. Delages 

 and H^rouard say " Ray Lankester a decrit k droit du 

 rectum un testicule qui s'ouvrirait k la marge de I'anus ; 

 mais Fowler a nie son existence." Whilst I thoroughly 

 agree with Prof. Delages in the propriety and usefulness 

 of citing the names of authors responsible for statements, 

 and admire the thorough and conscientious way in which 

 he has thus brought his work up to the latest date so as 

 to make it a really valuable source of references, I note 

 that it is difficult to be always exact in such citations. 

 Fowler had no opportunity for denying the existence of 

 the testis described by me in Rhabdopleura. Of its 

 existence there is no possibility of doubt ; it was ob- 

 served in several specimens, and figures of several of 

 these were published by me. All that Fowler said was 

 that he did not find it in certain specimens observed by 

 him. This is entirely in accordance with what I had 

 stated, since in by far the majority of living specimens 

 studied by me it was absent, and only present in ex- 

 ceptional individuals which happened to be in a state of 

 sexual maturity. 



I will venture also to enter a protest against the 

 citation by M. Delages of a genus of Protozoa based on 

 the "ciliated pots" of Sipunculus. Every one knows 

 that these are two-celled structures belonging to 

 Sipunculus itself, and not parasites. 



The plan of the " Zoologie Concrete " comprises 

 nine volumes royal octavo of about 500 pages each ; but 

 it seems to me impossible that the larger groups can be 

 treated with the same thoroughness as are those dealt 

 with in the two published volumes unless a much larger 

 number of volumes is produced. We are promised a 

 volume on the Prochordata in the present year, a volume 

 on the Coelentera in 1899, and separate volumes sub- 

 sequently on each of the following groups : — Echino- 

 derma, Vermes, Articulata, Mollusca, Vertebrata. 

 Whether the work can be thus completed or not, there 

 is no doubt that the volumes published are of consider- 

 able value, and their successors will be looked for with 

 great interest by all zoological colleagues of MM. Delages 

 and H^rouard. 



The proper limitations of size and the true scope of 

 zoological text-books form a subject which may be 

 endlessly debated. After all, is it not the fact that 

 Bronn's " Thierreich " is the only treatise which is 

 sufficiently comprehensive and detailed ? Do we not 

 know that it will never be finished, but that it must be 

 re-written volume by volume so long as zoology endures "i 

 And is not Gegenbaur's " Grundriss " the only really 

 masterly condensation and convincing exposition of the 

 great generalisations of comparative anatomy hitherto 

 written ? 



Gegenbaur's book is nearly twenty-five years old. A 

 brief survey of the genealogical significance of animal 

 structure is needed now, which shall as firmly and clearly 

 present the morphological doctrines of 1900 as did the 

 "Grundriss" present those of 1875, 



E. Ray Lankester. 

 NO. 1489, VOL. 58] 



WEATHER PREDICTION. 

 Die Wettervorhersage. Im auftrage der Direktion der 

 deutschen Seeivarte bearbeitet von Prof. Dr. W. 

 J. van Bebber, Abtheilungsvorstand der deutschen 

 Seewarte. Zweite verbesserte und vermehrte Auflage. 

 (Stuttgart: Ferdinand Enke, 1898.) 



SOME years ago Prof van Bebber put before the 

 world a popular account of the principles under- 

 lying weather prediction. His long experience at the 

 Deutschen Seewarte enabled him to give the latest 

 information concerning the processes employed in the 

 most authoritative manner, and the result was neces- 

 sarily a very interesting book. It is therefore not a 

 matter of surprise that this treatise should have run out 

 of print, and a second edition be peremptorily called for. 

 Such a result must, however, be gratifying to the Pro- 

 fessor, because he has recognised the fact, that the full 

 value of the information supplied to the public through 

 the weather bureau, supplemented as it is by weather 

 charts and tables, cannot be fully appreciated so long as 

 those for whose benefit such information is disseminated, 

 remain ignorant of the general principles of meteorology. 

 Guided by this motive, he has systematically endeavoured 

 to popularise the science, while working in the forefront 

 as a scientific meteorologist. His method of making the 

 information useful, and of instructing those who are 

 possibly far removed from a meteorological station, and 

 therefore thrown to a considerable extent on their own 

 resources, consisted in preparing a large number of 

 weather charts, something like two hundred in all, 

 arranged in a systematic order, in which might be found 

 represented the conditions of the weather obtaining at 

 any subsequent epoch. A judgment or forecast could 

 then be formed from the similar data supplied in the 

 book, and possibly the effect of local circumstances taken 

 into account. The same method is pursued in the 

 present edition ; indeed it has not been found necessary 

 to alter the maps in any essential particular, judging by 

 the dates to which they refer. 



If there be any who doubt the efficacy of the modern 

 system of forecasting the weather, or the utility of the 

 practice, it will be to a certain extent reassuring to learn 

 that, after twenty-two years' daily study of the weather 

 maps of Europe, Prof, van Bebber still relies confidently 

 on their accuracy and trustworthiness. And although 

 individual judgment may be disposed to prefer its own 

 conclusions in this matter of weather and the value 

 of forecasts, the question is one on which authority 

 should be at least heard with respect. For it is only 

 those who systematically compare the forecasts with 

 actual results, and who also are able to draw their 

 information from reports covering large areas, who can 

 judge of the success of a system which is more or less 

 upon its trial. One failure to issue a storm warning 

 from which suffering and disaster result, is remembered 

 far more easily than the many more numerous cases in 

 which the signal sends out its warning with due effect. 

 It must be admitted that there is apparently not the 

 same tendency to cover the Meteorological Bureau with 

 ridicule, when the forecast proves glaringly incorrect, as 

 was noticeable some years ago ; but this greater leniency 



