126 



NATURE 



[Junk 6, 1895 



-or even years, on board a ship, for men not well trained 

 10 such existence, except where the composition of the 

 staff is made with a sharp eye for compatibility and in- 

 compatibility of character. Especially the scientific leader 

 must be a man of imposing personality rather than of 

 special scientific competence, for it will fall to his share 

 to dictate in e\er)' case where conflicting tendencies 

 threaten to do away with social harmony. 



But though all this may be considered to offer con- 

 siderable difficulties in the way of execution, nevertheless 

 the future for oceanography will belong to such floating 

 biological stations, and the time is perhaps not so far 

 distant, when more than one of them will cross the 

 ■oceans, and supersede completely the now adopted sys- 

 tem of single-handed expeditions of young naturalists. 

 The necessity for such expeditions is doubtless existing, 

 in so far as it is better to vcy the solution of problems 

 regarding the tropics by travelling alone than by stay- 

 ing at home. And no doubt verj- many geographical, 

 ethnographical, geological problems have been greatly 

 advanced by competent travellers, and will furthermore 

 be advanced in the same way. Collections of animals 

 and plants have been made, mostly terrestrial, and the 

 systematic part of biology has had its due share. But 

 all more complicated studies, such as require more 

 technical appliances and preparations, remain in the 

 background, for the same reason which has forced us 

 already in Europe to establish well-organised morpho- 

 logical, physiological and chemical laboratories, both 

 inland and on the sea-shore. And if we cannot go on 

 without them in Europe, where the general conditions 

 for biological research are so much more ad\antageous, 

 we must certainly have them, if we wish to advance our 

 knowledge of tropical, terrestrial and marine organisms. 



Botany enjoys already some advantages through the 

 lx)tanical gardens in Ceylon and Java, and it is to be 

 hoped that the British and the Dutch authorities will 

 use their exceptional opportunities in both places to 

 establish some sort of regulations for their use by the 

 botanists of all nations. May it not be possible to 

 enlarge these botanical gardens by adding also some 

 facilities for research of animal morphology ? The 

 /Zoological .Station at Naples has a special part prepared 

 and equipped for morphological and physiological botany; 

 in the first place, of course, for marine alg;v, but any 

 other sort of botanical study, for which Naples offers 

 opportunities, might be undertaken there, and already 

 a valuable work on the cultivation of figs has been 

 greatly assisted by the Zoological .Station. No doubt 

 e\er)- naturalist who travels in Ceylon or the Sunda 

 .Archipelago receives the most valuable advice and 

 assistance by Messrs. Trimen and Treub, and perhaps 

 these most competent gentlemen would be the first to 

 advocate a larger endowment of their establishments in 

 the sense just now indicated ; science and research would 

 be certainly greatly benefited by it. 



All these dreams and perspectives are opened up 

 Ijcforc us when we are looking over the enormous mass 

 of new facts and new material for study brought together 

 by the Cliallcnacr. .\nd to think that there were only 

 four naturalists and one chemist on board all the years 

 long, and one of the naturalists died during the expcdi- 

 xion I It is, I think, only right to remember here that 

 NO. 1336, VOL. 52] 



two others of the gentlemen of the civilian staff so 

 heavily overta.\ed their strength with the often surely 

 \ery monotonous, and alwavs very hard work, that their 

 health broke down soon after their return, and they fell 

 victims to their enthusiasm. If it is only right to pay 

 the highest possible respect to Mr. Murray for his extra- 

 ordinary power of work, talent for administration and 

 competence in dealing with the special problems of deep- 

 sea deposits, and if we gladly recognise the excellent 

 work done by Mr. Buchanan, I think nobody will be so 

 ready as these two gentlemen to join here in thankful 

 remembrance of the share of work that fell to their late 

 companions. Sir Wyville Thomson, Prof. Moselcy, and 

 Dr. von Willemoes-.Suhm. .And may it be once more 

 permitted to the writer of these lines, who by right or 

 wrong claims some special title for it as a sort of inter- 

 national official of biological science, to utter the thanks 

 of science to the officers and men of the Clialtengcr, and 

 to the .Admiralty, and to the British (Government and 

 Parliament, and to the whole British nation for having 

 set the example to the world of one of the grandest and 

 most successful scientific expeditions that ever has been, 

 and most likely for considerable time to come will be, 

 started. .Anton Dohrn. 



OUR BOOK SHELF. 



Horses, Asses, Zebras, Mii/es. ami Mule }ireeding. By 

 \V. B. Tegetmeier, K.Z.S., and C. L. Sutherland, F.Z.S. 

 London : Horace Cox, 1895.) 



Thk first portion of the title of this interesting work is 

 somewhat misleading, for with the exception of some half- 

 dozen pages which deal mainly with the distinctions 

 between the horse and the other species of the genus, and 

 a description of the supposed new species known as 

 Prejevalsky's Horse, the book entirely relates to asses, 

 zebras, and mules. None of the varieties of the horse 

 which ha\ e been produced during the period of its long 

 domestication are referred to. \Vc mention this fact in 

 case the general reader should infer from the title of the 

 work that it was a treatise on the multitudinous domestic 

 \ arieties of the horse which exist in nearly every quarter 

 of the globe. 



The volume is conveniently divided into two parts. Part 

 i. is chiefly of zoological interest, and contains VC17 com- 

 plete and accurate descriptions of the existing species of 

 the genus known to modern zoologists under the name of 

 Equus, including, in addition to Prejevalsky's Horse, an 

 account of the still more recently discoxered Grevy's 

 Zebra. The engra\ings which illustrate the letterpress 

 are particularly good, and will greatly assist the student 

 in his endeavour to master the peculiarities of each 

 species. It concludes with a chapter on the hybrids 

 which may be produced by crossing the horse with the 

 other species of the genus Equus. 



.Attention should be directed to an assertion on the part 

 of the authors thai a remarkable and noticeable difference 

 exists in the period of gestation of the marc and ass. The 

 duration of gestation in the mare is well known to be 

 eleven months, and it has generally been .issumed thai it 

 was similar in the ass and zebra. The authors, howe\ev, 

 emphatically assert that in asses and zebras it usually 

 exceeds twelve months ; one of them, Mr. .Svitherland, who 

 is well known as an extensive breeder of mules, quotes 

 from his stutl-book eight instances of the period of gesta- 

 tion in the ,iss, the result in six cases of a single service, 

 the period varying from 358 to 385 days. It seems 

 strange that such a marked difference should have 

 hitherto escaped mention in all pre\iously published 

 works. 



