June 14, 1877] 



Brachiopoda 



HiEher Crustacea 



Ostracoda 



Copepoda 



Isopoda 



Cirripedia 

 Annelida 



Gephyrea 



Bryozoa 



Echinoidea 



Ophiuridea ... 

 Crinoidea 

 Hydromedusje 

 Corals 



Sponges 



Rhizopods 



Radiolarians ... 



NA TURE 



... Mr. Davidson. 



... Probably Prof. Claus. 



••• I Prof. G. Brady. 



... Mr. Henry Woodward. 



... Mr. Darwin. 



... Dr. Mcintosh. 



. . . Prof. Ray Lankester. 



... Mr. Busk. 



... Mr. A. Agassiz. 



... Mr. Lyman. 



... Dr. Carpenter and myself. ' 



... Prof. Allman. 



.. Mr. Moseley. 



. . . Prof. Oscar Schmidt and myself ] 



... Mr. Henry Brady. 



... Prof. E. Haeckel. 



"Now the only foreigners in this list are Dr. Giinther, Prof. 

 Claus, Prof. Agassiz, Mr. Lyman, Prof. Oscar Schmidt, and 

 Prof. Haeckel. If there is a better English authority than Dr. 

 Giinther on fishes, I beg his pardon for having overlooked him. 

 The crustaceans were to have been done by the late Dr. v. Wille- 

 moes-Suhm and certain considerations come in as to the use of his 

 plates and notes, which I need not discuss. I am not aware that 

 there is any one in this countiy who can be considered at 

 present an authority on recent Echinoidea. The choice perhaps 

 lay between Agassiz and Loven, but the reference collection at 

 Cambiidge is the best in the world in this department. There 

 is, so far as I know, no English authority on Ophiurids at pre- 

 sent. I prefer Oscar Schmidt's mode of treating the sponges to 

 that of any other author. I am not aware that any Englishman 

 knows the Radiolarians so well as Haeckel. There are a good 

 many departments not yet settled, and one or two other foreigners 

 may be added to the list. I should of course have most heartily 

 asked your assistance with the corals had Moseley not undertaken 

 them, but he has the preference as one of our staff, and he has 

 done excellent work. 



" I have submitted the principles on which I am working to 

 the best of my ability to the Treasury, and they have received 

 their sanction and that of the Council of the Royal Society. I 

 cannot recognise the importance of the geographical distribution 

 of naturalists, and with all respect for the dignity of British 

 science I must say I think that in this selection, which I con- 

 sidered entirely open, I have done it ample justice. 



" Believe me, very traly yours, 



" C. WvviLLE Thomson 



" 20, Palmerston Place, Edinburgh, March 27 " 



To this letter no reply has been received, and the sub- 

 ject might well have ended here. 



The objectors to the course pursued by Sir Wyville 

 Thomson would hardly advocate our assumption of a 

 spirit more narrow and illiberal than that of any other 

 country, and they will perhaps be interested in knowing 

 how a foreign Government has acted under quite similar 

 circumstances. 



The results of the two great recent scientific expe- 

 ditions fitted out in the United States, that of the 

 " Haslar," and the Exploration of the Gulf Stream, have 

 been distributed among special workers without any re- 

 gard to nationality. Of this we need no further evidence 

 than that afforded by the arrangements which have been 

 adopted for the examination of the very rich collections 

 made during the Gulf , Stream Expedition. These col- 

 lections have been allocated as follows : — 



Halcyonaria ... A. KoUiker Wiirzburg. 



Annelides E. Ehlers Gottingen. 



Sponges (part) ... O.Schmidt Strassburg. 



Sponges (part) ... E. Haeckel Jena. 



Holothurians ... E. Selenka Leiden. 



Polyzoa F. A. Smitt Stockholm. 



Mollusca J. Gwyn Jeffreys London. 



Hydroids G. J. Allman London. 



Starfishes E. Ferrier Paris. 



Crustacea Alph. Milne Edwards... Paris. 



Fishes F. Steindachner Vienna. 



Cephalopods 

 Brachiopods 



Corals 



Ophiurans ... 

 Echini 



J. P. Steenstrup 

 W. H. Dall... 

 L. F. Pourtales 

 T. Lyman 

 A. Agassiz ... 



119 



Copenhagen. 

 Washington. 

 Cambridge, U.S. 

 Cambridge, U.S_ 

 Cambridge, U. S 



It will be thus seen that out of the twenty-two zoologists 

 among whom the collections of the Challenger have been 

 distributed seventeen are English ; while out of the sixteen 

 to whom the American collections have been assigned, 

 four are A7nerican. 



ELEMENTARY PHYSICS 



Matter and Motion. By J. Clerk-Maxwell. (Society for 



Promoting Christian Knowledge. London, 1876.) 



THE recent appearance of a swarm of elementary 

 books on physics, some of which at least are written 

 by well-known authors, leads to some very curious in- 

 quiries and speculations : for, though treating in the main 

 of the same parts of the same subject as does the work we 

 are specially dealing with, and addressed professedly to 

 the same class of readers, they have comparatively little 

 in common with it. To a certain, even a considerable, 

 extent, this difference is of course due to the idiosyn- 

 crasies of the authors ; but, after all allowance is made 

 for these, there is still a most notable divergence. It 

 will be both interesting and profitable carefully to 

 consider in what this divergence consists, and what is 

 its probable origin. For it is not too much to say that 

 an intelligent reader of Clerk-Maxwell's book, had he 

 no other source of information, would be utterly unable to 

 answer any one of hundreds of questions which might be 

 framed (without " dodge " or " trap ") by a qualified 

 examiner, directly from the text of the others. It is true 

 that such questions would be artificial rather than natural 

 — bearing more upon old and cumbrous dogmatic fallacies 

 than upon the actual facts of science. But if the reader 

 of Clerk- Maxwell's book would be at a loss when examined 

 from any of the others, the student who relies merely upon 

 one (or even all) of these would hardly even understand 

 the meaning of a question put directly from Clerk-Max- 

 well's. The main origin of this divergence is to be found 

 in the steady progress of knowledge in aU departments of 

 true science ; even the most elementary. And, bearing 

 this in mind, we may give an almost complete statement 

 of the case by saying that Clerk-Maxwell's book properly 

 belongs to the second half of the present century, while 

 his rivals give us that of the first half only. These give 

 us again the elementary " Mechanics " of our student days 

 (more than a quarter of a century ago) very little changed 

 —though where changed, often changed for the better— the 

 first gives us what is emphatically the science of to-day. 

 Possibly enough, in the beginning of the twentieth century 

 even Clerk- Maxwell's book may appear a little antiquated ; 

 but it is hardly to be imagined that the te.xt-book of that 

 not very distant future will differ from Clerk-Maxwell's 

 to anything like the extent to which that differs from its 

 competitors. At least if there be anything like so a great 

 difference it will depend upon some wholly new informa- 

 tion as to the intimate nature of matter or energy, 

 certainly not upon a mere difference in the mode of 

 treatment. 



The immense steps taken by Galileo and Newton (to 

 mention only two of the chief workers) in the simplifi- 



