HARUWICKE'S SCIENCE-GOSSIP. 



41 



that the microscopical examination of the stomachs 

 of diptera belonging to the order Syrphida showed 

 them to contain large quantities of pollen-grains, 

 especially of pants belonging to the order Compositce. 

 Entomologists had expressed a doubt as to whether 

 it was possible for insects possessing only a 

 suctorial proboscis to devour such solid bodies as 

 pollen-grains ; but Miiller believes that the trans- 

 verse denticulations found in the valves at the 

 end of the proboscis of many of the diptera are 

 especially adapted for chewing pollen, and for 

 dividing the threads by which the grains are often 

 bound together. 



Genekation of Eels. — On this very interesting 

 and recondite subject we have had very discordant 

 opinions, from the father of Natural History to the 

 present time. Yarrell, with the assistance of Jessie, 

 about twenty or thirty years since, made number- 

 less observations, and concluded that eels produce 

 their young like other bony fishes. Owen supports, 

 or rather reiterates, this view. But in 1848 G. 

 Schluesser, as reported by Van der Hoven (vol. i. 

 p. 39), made researches which tended to prove that 

 male eels are still unknown. Hermaphroditism in 

 fishes was only recognized as an abnormal pheno- 

 menon occurring occasionally in a few species, and, 

 according to Dufosse, regularly in Serranus hepatus, 

 S. scriba, and S. cabrilla. Lastly, as reported in 

 the Journal of Anatomy, May, 1872, p. 447, an 

 Italian physiologist, G. B. Erolani, asserts the 

 constantly perfect hermaphroditism of the eel. In 

 December the testes and spermatozoa acquire com- 

 plete development, with well-developed ovaries in 

 the seli'same fish. The ova and spermatozoa are 

 discharged into the peritoneal cavity, so that the 

 ova are fertilized before their escape from the body ; 

 and all this only in winter and in salt water. Thus 

 the question afi'ords an interesting and important one 

 for inquiry by naturalists using the microscope at 

 the seaside. — Q. F. 



The Fresh-water Polyp. — We omitted to 

 state, in Mr. Fullagar's interesting article on this 

 subject last mouth, that the "Spermatozoa of 

 Hydra" (fig. 17) were drawn by Dr. Gulliver, E.R.S., 

 from that gentleman's own observation. 



BOTANY. 



Herbaria. — A few words respecting the con- 

 struction of botanical collections would, I think, be 

 generally useful, and especially to beginners, who 

 are often daunted in their endeavours to collect, by 

 the apparent complexity of constructing an her- 

 barium. 1 think the few following suggestions, if 

 adopted, will be found to succeed. The collector 

 should first procure some flat boxes, of cardboard 

 or thin wood, say 1 in. or \\ in. in depth, of various 



sizes, corresponding of course to the kind of plant 

 to be introduced. The plants and flowers are laid 

 out upon sheets of paper ; the paper to have slits 

 cut in it to introduce the branches of the plant, or 

 slips may be gummed over, though the former way 

 is, I think, preferable. Do not gum the plant to the 

 paper. This is important, as, if gummed, they cannot 

 possibly admit of a thorough and ready examina- 

 tion. The plants should now be named, and 

 grouped together, according to their families and 

 genera. Each genus should be numbered. The 

 boxes should be marked in series, according to the 

 letters of the alphabet, and a certain number of 

 genera must be introduced to each series, say fifty. 

 Thus the first series would be, Genera A, 1—50. 

 The first series of boxes marked A would thus 

 contain fifty genera. And when we have to add 

 more species to any genus, the box of such genus 

 will admit of the introduction of such species ; for 

 if the box be already filled, the topmost genus has 

 merely to be shifted into the bottom of the next box, 

 and thus further them through the whole series of 

 cases ; and thus we should always be enabled to add 

 fresh species, and introduce them in their proper 

 place, with very little trouble. The first series of 

 cases, A 1—50, being completed, a list must be 

 now made of them, and they can be stowed away, 

 all the smaller cases to be put into one large one ; 

 and another series is commenced, viz. B 1 — 50 5 

 and so on. Upon the paper of each plant should be 

 given the common name, besides the scientific name, 

 and some description, as to where found, by whom 

 given, and all other particulars. These notes, be it 

 observed, are of the last importance, because they are 

 essential to the us'>fiilness of the Herbarium. The 

 plants may be poisoned with corrosive sublimate, or 

 a little camphor may be put into bags and 

 hung in the cases. But if the cases be kept dry, 

 the flowers and plants will be found to keep 

 admirably as a rule, without any such precaution. 

 Perhaps this short account may not be so clearly 

 understood as I could wish; for it is always 

 difficult to describe that which is to be carried out 

 in practice, and only properly learnt by experience. 

 — IF. S. Palmer. 



Arabis stbicta.— Mr. Lees, in his communica- 

 tion to you on " Recent Records of Rare Plants," 

 refers to Arabis strida, and presumes it must be 

 almost, if not quite extinct, as it was not discovered 

 by him here in 1871. 1 have, for several years, 

 noticed this plant with much interest. There are 

 several spots in this locality where it may be found, 

 either a few scattered specimens or small patches 

 of a dozen or more. In 1872 it was more abundant 

 and luxuriant than I had ever seen it before. Over 

 a space of a square yard or two, in one place, were 

 at least fifty plants, the pale petals being distin- 

 guishable at a considerable distance. Very many 



