54 



NA TURE 



[May 17, 1894 



undergoing modification in civilised man, and parts not used to 

 any extent are being deprived of the supply necessary to healthy 

 growth. It is ntiucli to be feared that the teeth, though so 

 essential to the welfare of the body, are in this predicament. 

 But we are sidly in need of more definite information than is 

 »t present available, and it i* partly in the hope that some of 

 the readers of N'aturr, who hav'e opportunities which t do 

 not posse;?, may be induced to test this and other ideas relative 

 to the increase of caries, that I have written on the subject. 

 The whole question is at present much obscured by misconcep- 

 tions due to i.;norance. One fact, however, emerged only too 

 clearly from Dr. Wilberforce Smith's investigation, namely, 

 that while the giinJing teeth of civilised men of middle age are 

 either missing or practically useless for th:ir purpose, the 

 ancients enjoyed a perfect set of teeth till advanced years, and 

 modem savages enjoy the same blessing. 

 Clapham, May 10. Arthur Ebbels. 



Johannes MtiUer and Amphioxus. 



The story of Miiller's Neapolitan visit in search of 

 Amphioxus, as copied in Nature (May 3, p. 14) from the 

 I.ancel, belongs to the category of those that are hen Irovalo or 

 the reverse. To anyone acquainted with the works of this bril- 

 liant morphologicil genius th; tale b*ars internal evidence of 

 entire lack of foundation. 



Miiller's chief memoiron .\mphioxus appeared in the .llihaiul- 

 liingen d;r Birlincr AkaUmit 1842. If Prof. Todaro had ever 

 read the original, or an earlier noie in the Berichle 1839, he 

 would scarcely have related the story. Miiller's work begins 

 with an historical summary of previous researches on the animal, 

 and in particular he relates {Btrichle 1839. p. 199) that the first 

 specimens he examined were obtained from Prof. Retzius. 

 Moreover, Costa's description, mentioned by Prof. Todaro as 

 being the immediate cause of Miiller's expeditious tri|) to 

 Naples, apptiirei ill 1839, an I in iht same year Mii'ler pub- 

 lished observations on the two specimens given him by Retzius. 

 At this period he was in ignorance of its occurrence at N.iples, 

 for (p. 200) he says it has been found "on the English, 

 Norwegian, and Swedish coasts." His chief work — the one be- 

 fore mentioned — was carried out on lifing specimens got by 

 Midler himself near Gothenburg, on the Swedish co.ast, and. as 

 is well known, and also expressly stated by himself, he worked at 

 the microscope for twelve days in order to complete his task on 

 the spot. The evidence goes to show that .Midler obtained no 

 Amphioxus — not even the one he is credited with 1 — from 

 Naples nntil his work was completed ; and (p. 81, foot-note) 

 he remarks : " In Naples the capture of the animal is very easy 

 close inshore, for it lives in great numbers in the sandy ground 

 of Posilipo. In 1842 I brought back from Naples owr ICXX) 

 sf'tcimem in spirit." 



If the journey referred to ever look place, there is no record 

 of the one specimen in any of his works, and .Vlviller, who could 

 sacrifice a very rare Pentacrinus to the scalpel, was not the 

 man to spare an .\mphioxus. It must indeed have been a 

 "miraculous driught" that yielded only one specimen o( 

 Amphioxus off Posilipo. 



However " intere ting " and amusing the story may be to 

 those who have a preference for fiction, it is to be regretted 

 that, with n> I asis of fact to support it, a zoologiit shoild have 

 lold it of one whom zoology will always rank as a chieftain 

 amongst her greatest sons. To many of us, who regard Miiller 

 with something akin to reverence, the fable it less inleresling 

 than painful. J. B. 



The Scandinavian Ice Sheet. 



iK reply to the letter of Prof. T. G. Uonney (Nature, vol. 

 xlix. p. 338), which 1 by chance have read to day, concerning 

 the difTiculiy of explaining how the Scandinavian land-ice could 

 have crossrd the 'Icrp channel of Skagi.-rak and Kattegat, and 

 havr -- *- ■ I ■'"■ '■ ■• Anglian coasts, I should like to remark 

 that ■ ' new to mc. and will exist after it has been 



cxpl.i ■■stream from Norway could have crossed 



the named ch.innel and ex'ended over Denmirk and North- 

 western 'ieimany. It i«, however, an undmpuled fact thai 

 certain Norwegian boulders are very common in the most 

 norlhein pa"'* of lylland, and from there dispersed over 

 the whole lylland (though their rarity incrcaici with dis'.ance 



NO. I 28 I, VOL. 50J 



from Norw.ay), the northern parts of Fyn and Sjcetland, over 

 Slesvig and Molstein and North-western Germany from 

 Fehmarn towards the west, furtherover Djtchl.ind a ul Belgium 

 to several localities at the English east coast, under such condi- 

 tions that they could not have been transported by floating ice. 

 It is consequenily a f.ic. that the ice-stream from Norway has 

 crossed the named channel. I think, therefore, that the best 

 explication is that the Skagerak channel in its p-esent condition 

 was at first formed after or during the period of largest glacia- 

 tion, to which the Norwegian ice-slream belongs, but before the 

 Baltic ice-streams, both of which, I suppose, are posterior to 

 the greatest extension of the land-ice. The chief reason 

 for the formation of these ice-streams is the exislence of the 

 above-named channel, which has prevented the ice-stream from 

 Norway from extending over Denmark for the second time. 

 Copenhagen, May 2. Victor Madsen. 



The Earliest Mention of Dictyophora, 



TwAN Chi.no-Siiiii's "Miscellanies," compiled in the ninth 

 century A.D. (Japanese edition, 1697, book xix. i\ 7). has the 

 following note : — " In the loth year of the perio 1 (Ta- Tiing (544 

 A.I). )a fungus grew in Yen-hiang Gardens owned by the Emperor 

 Kiin-Wan. It was eight inches long with a black head resem- 

 bling the fruit (that is, the Torus) of Eiiryale ferox : stem 

 hollowed through inside like the root oi Xeliiinbium spt'cicsum ; 

 skin all white except briow the root, where it was slightly red. 

 Portion like the fruit of Euryale had below a j )int like that of the 

 [ bamboos, and was removable ; from the joint a sheet was 

 [ developed, simulating a network, five or six inches in circum- 

 ference, surrounding the stem in the manner of a bell, but distant 

 and separate from it. The netwoik was line and lovely, and 

 also removable from the stem. It is allied to Weiliichi (the 

 Auspicious Fungus of Graveness and Pleasure) of the Taoist 

 writings. " This description seems to have been passe I over by 

 readers as a mere fiction, but I find that it agrees very well with 

 the figure of a Dictyophora, and may probably be the eirliest 

 mention of it. \ Japanese botanist, Rr./.in Sakamoto, has 

 figured the two forms of Dictyophora in his " .Monograph of 

 j Fungi" (1834, vol. ii. p. 15), but has not referred to the ab)ve- 

 cited description. Ku.M.VGUSu MiNAKATA. • 



M.iy 4. 



The Scope of Psycho-physiology. 



I HAVE no wish to enter into a triangular duel with Or, 

 Titchener and " the writer of the note " who has provoked his 

 fire. But since my name has been introduced, a word or two of 

 explanation seems necessary. 



Some time before Or. Titchener discharge.! his first barrel, I 

 was requested by the editor of this journil to contribute a 

 popular article on "the scope of psycho- phvsiol5.;y," In 

 com[ilying with his request, I accepted (i) the conditions 

 implied by tlie word popular, which ii) doubt laid me op^--n to 

 the criticism ihat my " whole treatment " was "a little gcner.il 

 and superficial " ; and (2) the title suggested to me, since 1 

 regaded it .as comprehensive and not specially provocative of 

 terminological controversy. C. Liuyd Morc.an. 



Bristol, May 10. 



The Aurora of February 22. 



The splendid aurora of February 22-23 began on the 

 Pacific coast of North Americ\ on the former date, extending 

 unusually far south in Californii, New .Mexico, anl Arizona, 

 but did not become con^^picu lus on the eastern half '<! the 

 continent until the day following. The earth currents afTecling 

 the telegraph lines were troublesome west of Chica;o exclusively 

 on February 22 also, not being felt cast of that point until the 

 day following. This localisation of the aurora in longitude 

 has been noted in numero'is other instances as well. An 

 arrangement has been made to secure reconls of the geo- 

 graphical distribution of earth current disturbances on the linei 

 of the Wislern Uniim Telegraph Company, which extend very 

 widely over I he North American continent. From wliat 

 appears in the case above described, such records are likely to 

 prove to be of very great inlercsl. 



April 30. M. A. VsEDKR. 



