Dec. 30. 1875] 



NATURE 



167 



that the observations of Kamerer of Niimberg (Camerarius) 

 anticipated by two years the publication of Ray's "Historia 

 Plantaram, " I must refer him and any of your readers who are 

 interested in the subject to Sachs's "Geschichte der Botanik." 



Linnreus (" Amcenitates," vol. i. pp. 329, 330) thus sums up 

 the relative merits of Millington, Grew, Ray, and Camerarius : 

 "Thomas Millington, equesAnglus, Professor Savilianus, primus 

 videtur, qui insigni cura in banc veritatem eruendam incubuit, 

 viamque aperuit experientissimo Grewio. Nehemias Grew, in 

 anatome Plantarum, sexus diversitatem et fecimdationem plan- 

 tarum per farinam mascide scrutari conatus est ; cujus hypo- 

 thesibus, album addidit calculum temporis sui botanicus eximius 

 Raj us. Rudolphus Jacobus Camerarius primus perspicue demon- 

 stravit sexum et generationem,[quamvis non dubii fuit ipse expers 

 de hac veritate, quod si moverant experimenta quos fecerat in 

 Cannabe." 



Now as to Theophrastus. Your correspondent makes much 

 of the "prolifick virtue " ascribed to the pollen-grains by Grew. 

 No one, however, can have read the writings of the early Greek 

 and Roman naturalists without having learned, that not only did 

 they distinguish male and female flowers, but also ascribed a 

 •' prolific virtue " to the pollen. Without troubling your readers 

 with a Greek quotation, let us hear what a commentator on 

 Theophrastus says: — "Theophrastus ait, fructum in palma 

 feminae perdurare nunquam posse nisi florem maris cum pulvere 

 super eam concusserint ;" and again: "In palma maris et 

 foeminse coitus sit ;" or again, Pliny : " Adeoque est veneris in- 

 teliectus, ut coitus etiam excogitatus sit ab homine ex maribus, 

 flore, et lanugine, interim vero tantum pulvere insperso 

 feminis." 



I hardly think your readers generally will agree with 

 "A. B. C." in his opinion that "time, paper, and ink are 

 wasted ' in a discussion of a historical point of some interest. 



Dec. 24 Alfred W. B enxett 



Saw-fish Inhabiting Fresh Water 



Ix Nature, vol.xiiL p. 107, Mr. Wood, of Manila, writes on 

 " Saw-fish inhabiting fresh water," in the Laguna de Baij, 

 Luzon, as on something curious and new. But this fact was 

 kno«Ti long ago ; not only do sharks live in fresh water there, 

 but also elsewhere on the globe. As one who mentions the saw- 

 fish in the Laguna de Baij, I only name the famous de la Giron- 

 niere (" Aventures d'un Gentilhomme Breton," 1857). He says, 

 p. 102 : " Deux poissons de mer se sont acclimates dans les eaux 

 douces du lac : le regitin et la scie. Le premier est heureusement 

 assez rare, mais le second est tres abondant." 



The species of saw-fish mentioned is Pristis perrotetti, a species 

 of very wide distribution ; it has been collected in the Atlantic 

 (West Indies), in the Indian Ocean (Zambesi), in the China Sea 

 (Borneo), &c. 



When on Luzon in the year 1872, I succeeded in procuring a 

 series of specimens on the spot, which I brought home ; they 

 are from two to three feet long, but I saw, myself, at the fish- 

 market of St. Cruz a specimen of about twenty feet in length. 

 Quantities are to be seen on every market day in St. Cruz, the 

 flesh being very cheap on account of its bad and dry quality, and 

 only the poor mountaineers like it as food. 



I took some trouble to get those smaller 'specimens home, 

 because I fancied that they might possibly differ from the 

 marine specimens (Bay of Manila). But an accurate comparison 

 showed no difference at all, and therefore the changed conditions 

 seem to have had 110 influence on the external features of the 

 species. 



The saw-fishes are said to fight violently with the crocodiles, 

 which occur in lai^e quantities in the Laguna, and I do not 

 doubt the fact A. B. Meyer 



Dresden, Dec 23 



Spectrum of Fish-pigment 

 I HAVE lately observed the spectrum of a pigment-colonr 

 found under the scales in fins and tail, mouth and eyes, of a 

 small smelt-like fish found in St, Vincent's Gulf, S. A. They 

 are commonly known as the Weed fish, but Mr. Waterhouse, 

 our Curator, informs me they are xYif^Odax radiatus, O.Jrenatus, 

 O. Richardsonii. These fish are perfect little gems for colour, 

 being of a bright blue green (nearly blue) in O. Richardsonii, 

 and about the eye most splendid ; black centre, brilliant orange 

 ring, outside of which is a most briUiant turquoise blue ring set 

 in deep brown. 



Finding this colouring matter stained paper, I examined the 

 scales and fins by spectroscope, and noticed a deep band that 

 appeared to correspond with the deep band of chlorophyll. I 

 send a sketch of the respective sp»ctra and a bulb and tubs of 

 the pigment in solution, which, with the pieces of tail and fins, 

 I trust you will receive in good condition. I do not place 

 much faith in it remaining clear and brilliant ; the heat of the 

 ship may possibly destroy or alter it. Yoa will notice the solu- 

 tion is rather bluer than chlorophyll. This pigment is nitro- 

 genous, is destroyed by heat, chlorine, acetic acid, alkalis, am- 

 monia, and alcohoL It is soluble in water and sea-water. 

 Sidphuric acid precipitates it with albumen of fish, but does not 

 destroy colour. Light bleaches it Its chemical properties are 

 therefore distinct from those of chlorophylL 



I consider some interest attaches to this from the fact of the 

 Parrot-fish {Labrichths Richardsonii) being marked with blue 

 stripes containing the same colouring matter ; also the scales and 

 parts in Odax coloured orange give a green tint almost idenrical 

 in shade to chlorophyll. This yellow or orange does not give 



BvJb- 



Spectra with keroslne flame on edge of Odax pigment and comparison 

 with chlorophyll. 



Dividing the Solar spectrum into 10,000 parts from A. bright keroane 

 flame on edge gives as above. The chlorophyll band is rather lighter in the 

 centre ; when solution is dilute it divides into two fine lines. ^^1dth of 

 strong band, 493. 



The Odax Pigment does not resolve into two lines. The centres of these 

 two great bands Odax Chlorophyll are only forty-five apart. Width of 

 band, 665 : rather nebuloHS, espedaly at end of greatest refraction. Some 

 very faint bands accur each side of O, and continue to end of nebulosity 

 to 2,550. The bulb gives the above figure. The tube a much narrower 

 band, but centre coincides with bulb. 



any band or interfere with the spectrum of the pigment, except 

 so far as its mere colour and general absorption at blue end 

 arising from such colour. 



Now as chlorophyll has been said to be found in some infusoria;, 

 which I doubt, it is just possible that this or similar colouring 

 matter is taken for it. I have been rather curiotis in examining 

 animal greens in shells, and a native green silk we have here, also 

 in the Emu ^g-shell, but cannot find the slightest trace of chlo- 

 rophyll band, and until I met with this I concluded no animal 

 green yielded any band that could be mistaken for chlorophyll, 

 and that therefore the spectroscope was an unerring test for dis- 

 tinguishing between vegetable and animal oi^nisms. This spec- 

 trum of Odax pigment, which possibly I may find in other species 

 of fish, Actiniadse or Medtisae, many of which are beautifully 

 coloured, is therefore so far of interest. I trust these remarks 

 may be interesting and lead to some inquiry in this direction. 



The dry pieces of fins and taU, also a piece of stained paper, 

 will show well if mounted in balsam. If the colour is not deep 

 enough, cross the layers one over the other until sufficient depth 

 of shade is obuined. I use half-inch object glass in microscope 

 except for scales and spots, when I use quarter, and shut out aU 

 other light ; single scales then show the bands welL 



George Francis 



Laboratory Institate, Adelaide, Oct 9 



Function of the Ocelli of Hymenopterous Insects' 



My brother, Fritz Miiller (Itajahy, Prov. St. Catharine, South 

 Brazil), in his letters to me, has repeatedly started the question 

 whether the size of the ocelli of h)rmenopterous insects is 

 not dependent on thdr nocturnal habits. He supports this 

 opinion by the following observations : — 



