570 



NATURE 



{Oct. 26, 1876 



Potomac River to the south, the Ohio River in the west, and 

 many other places ; {5) The Heteropygii have three genera (as 

 understood by Putnam, the only naturalist who has thoroughly 

 studied them) confined to the western and southern states ; 

 (6) The genus ParaUbrax is an entirely marine one, very closely 

 related to Serranus {cabtilla, scriba, &c.), and is represented 

 extensively on the western coast of America, as well as elsewhere 

 in the Pacific Ocean ; (7) Huro nigricans (the only species) is a 

 mere synonym of Grystes or Micropterus nigricans, which extends 

 to Florida in the south-east, and Mexico toward the south-west ; 

 (8) Pileoma is a later name for Percina ; (9) Bryttus and 

 (10) Poinotis are not Percidcv according to most American 

 authors, nor according to Dr. Giinther's recently promulgated 

 views (the vertebrae being only A 10 + C 14), and belong to a quite 

 peculiar family ; [\\) Hypoddus is a vaisxiomQr ior Hopladelus ; 

 (12) Thalelchthys is as much a marine genus as Osmerus (Smelts) ; 

 there is no such restriction at all as indicated by the remarks on 

 the distribution of (13) Moxostoma, (14) Pimephales, (15) Hybo- 

 rhynchus, and (16) Rhinichthys on the one hand, and (17) Eri- 

 cytnba, (18) Exeglossum, (19) Leiuosomus, {= Semotilus), and 

 {20) Carpiodes on the other ; and the categories might indeed, as 

 to most causes, be almost reversed ; (21) Mylaphorodon is a 

 misnomer for Mylopharodon. The number of genera enumei ated 

 as peculiar might, too, be very safely more than doubled, and by 

 reference to Giinther's work and subsequent corrections, Cen- 

 trarchus, Ptyonotus (= Triglopsis), and Hysttrocarpus could 

 have been added. All these errors might have been prevented 

 if Mr. Wallace had been familiar with ichthyology and its lite- 

 rature. The paragraph cited also quite conceals the remarkable 

 distribution into secondary faunas of the American genera, and 

 is calculated to entirely mislead respecting the contrasts between 

 North America and the Old World. His use of the term 

 " Eastern States" (instead of "Eastern Province," as Baird calls 

 the division meant) is confusing, inasmuch as it is a geographical 

 designation for a particular group of states. 



Smithsonian Institution, Washington, Thko. Gill 



September 21 



" ■ The Self-Fertilisation of Plants * 

 Under this title there is an article in Nature, vol. xiv. 

 p. 475, mentioning some observations on flowers, and concluding 

 thus:— "In view of these examples .... it can hardly be that 

 colour, fragrance and honeyed secretions in flowers have been 

 developed solely to secure cross- fertilisation." In reply to this 

 article it may be worth showing that of the examples relied upon 

 the first and last are most probably incorrectly observed and 

 erroneously interpreted, whilst the others are of no consequence 

 at all, so far as the good effects of cross-fertilisation are con- 

 cerned. 



First, the flowers of Browallia data have been most accurately 

 described by F. Delpino ("' Ulteriori osservazioni sulia dicogamia 

 nei regno vegetale," Parte I. p. 140-143), and this excellent 

 observer has fully convinced himself that it is cross- fertilised 

 whenever it is visited by Lepidoptera or Bombylius. 



Claytonia virginica and Ranunculus bulbosus simply confirm the 

 well-known fact that many flowers have recourse to self-fertili- 

 sation when not visited by insects (see H. MUUer's " Befruch- 

 tung," p. 443-448, Nature, vol. viii. p. 433, vol. ix. pp. 44, 



64, vol. X, p. 122). .,••11 



As to the last example. Ranunculus abortivus, it is madmissible 

 to conclude from the fact that one has not observed visitors on 

 a plant, that this plant is wholly neglected by insects. 



With regard to the article as a whole, it seems to me some- 

 what rash to call in question a comprehensive and well-founded 

 theory on the basis of a few superficial observations. 



Lippstad, October 20 Hermank Muller 



The Proposed Zoological Stations at Kiel and 

 Heligoland 



In Nature, vol. xiv. p. 535, there appears amongst the 

 occasional Notes, a short report of a proposal of the Association 

 of German Naturalists to found two new Zoological Stations at 

 Kiel and Heligoland. The establishment of such stations could 

 not fail to be of immense service to biology, but it is much to be 

 regretted that the Association is inchned to put aside the claims 

 of the present Zoological Station at Naples in favour of these 

 two new institutions. To act in this way would be both unwise 

 and ungenerous : unwise, because a station on the shores of the 

 Mediterranean can obtain a great variety of forms which are not 



to be found in the North Sea and the Baltic ; and ungenerous 

 because the Naples Station has been the means of proving both 

 the value and feasibility of such institutions, and without it the 

 present proposals would never have originated. It is indeed 

 surprising to see a body of German naturalists refusing their 

 support to an institution like that at Naples, which has already 

 rendered such signal services to biology, in which so many of 

 themselves have made important discoveries, and which is, more- 

 over, founded almost on the site of the classical investigations of 

 Kolliker, Gegenbaur, and Hceckel. 



It is to be hoped that the Commission appointed by the Asso- 

 ciation to draw up a memorandum will see their way to urging 

 the claims of the existing Zoological Station at Naples without 

 thereby interfering with the prospects of the similar institutions 

 which it is proposed to found. F. M. Balfour 



Trinity College, Cambridge 



The Flame of Chloride of Sodium in a Common Coal 

 Fire 



Mr. Hardman, in Nature, vol. xiv. p. 506, gives an 

 account of a number of experiments which he considers to bear 

 out the old theory that the blue flame produced by throwing 

 common salt on a coal fire is due to carbonic oxide. His letter 

 induces me to give an account of a series of experiments which 

 I made last winter, in company with Mr. R. A. Lundie, and 

 which led me to an exactly opposite conclusion. Our experi- 

 ments were all made with the help of a spectroscope, no depen- 

 dence being put on observations made with the naked eye : — 



1. We examined, with the spectroscope (which was a small 

 direct-vision one), a very distinct blue flame of CO, burning in 

 a coal fire ; this, as far as we could see, gave no bright lines. A 

 little common salt was then put on the fire, when at once a very 

 marked spectrum appeared, the most characteristic part of which 

 was a pair of bright lines in the blue, and another pair in the 

 violet beyond the spectrum of the glowing coals, against which 

 the flame was generally seen. This flame was very persistent, 

 and frequently long after rhcjlams had ceased to be distinguish- 

 able, the spectrum was still quite marked. 



2. We did not succeed in getting the spectrum with other 

 salts of soda, such as carbonate, phosphate, and borate ; nor yet 

 with microcosmic salt, while on the other hand, with other 

 chlorides and chlorates, suchasKCl, KCIO3, andNH4Cl almost 

 exactly the same spectrum was obtained, and with bromide of 

 potassium a very similar, if not an identical, spectrum was also 

 obtained. 



3. We were able, but with more difficulty, to get the charac- 

 teristic spectrun:), when a blow-pipe flame was made to p!ay 

 down on chloride of soda, or ammonia, l>ing on an iron plate ; 

 and in this case it was observed that the blue flame seemed to be 

 produced only when the flame which had passed over the salt 

 came to a colder part of the plate where there was more salt. 



Want of lime has prevened me from continuing my experi- 

 ments, and I do not venture to suggest any theory to account 

 for the phenomenon. It is possible that part of the blue blaze is 

 due to carbonic oxide, but I am convinced that this is not a com- 

 plete explanation. Neither do I think that Mr. Miiller's expla- 

 nation (Nature, vol. xiii. p. 448) is sufficient, though a number 

 of our earliest e<periments, in which a brass plate took the place 

 of the iron plate (in experiment 3), certainly favour this explana- 

 tion to a certain extent. The flame thus produced gave the 

 characteristic spectrum very brightly, but at the same time new 

 lines (copper) appeared in the green. I would add that I have 

 as yet been unalale to get satisfactory measurements of the posi- 

 tions of the lines, the spectroscope I used for most of my ob- 

 servations having no micrometer nor scale. 



C. MicHiE Smith 



Keig, Aberdeenshire, October 13 



OUR ASTRONOMICAL COLUMN 

 The Intra-Mercurial Planet Question.— M. 

 Leverrier has made a further communication to the Paris 

 Academy on this subject. With the view to testing the 

 sufficiency of the method employed, to afiford a guide for 

 prediction of future transits of such a body over the sun's 

 disk, admitting that the observations in which appre- 

 ciable motion is recorded really refer to an intra-Mer- 

 curial planet, he applies it in the case of Mercury. Tran- 



