=56 



HARD WICKE 'S SCIENCE- GOSSIP. 



leaf, sepal, iSzc, boil it for two or three minutes in a 

 solution of caustic potass, then let it soak for a short 

 time in cold water, after which place on a slide and 

 draw off superfluous water with a pipette, pour on 

 the object two or three drops of glycerine jelly, and 

 warm it gently over a spirit-lamp, so as to allow the 

 jelly to flow under the object ; then put on the cover 

 and fasten down with a wire clip ; and to remove air- 

 bubbles hold the slide over the flame of a spirit-lamp 

 until the jelly boils : when cold, clean off the slide and 

 finish as usual. Transparent objects do not i^equire 

 boiling in caustic potass. To mount the crystals in 

 rhubarb I should prefer to make a thin section in a 

 section-cutter, omit the boiling process and proceed 

 as above. These crystals [i.e. in the rhubarb), are 

 SpJucr aphides, and should not be confounded with 

 Raphides ; needle-shaped bodies usually occurring in 

 bundles, and differing perhaps as much in chemical 

 composition as they certainly do in value as a 

 character in systematic botany. — .5". Baker, 

 Chichester. 



ZOOLOGY. 



Chameleon-like Changes in the Frog. — 

 On the 7th October I fed my pet frog Paul with a 

 few choice worms, finishing off with a plump blue- 

 bottle fly. I noticed at the time he was of a beau- 

 tiful lemon-colour, with drab spots and markings. 

 I may mention that, after a long search, I discovered 

 him in a secluded spot in the vivarium. After par- 

 taking of his repast, he indulged in a bath. "Within 

 the hour I again visited Paul ; he was then of a dark 

 drab colour, or nearly black. I have frequently no- 

 ticed this change of colour, but not so decided and 

 in such a short space of time as in this instance. 

 Paul has been with us now over six years. Is this 

 sudden change commonly known ? I have not read 

 works on the frog (St. George Mivart's, for instance). 

 If the above is of sufficient interest for your columns, 

 oblige by recording it. — J. J. M. 



Plants, &c., for Reptile Vivaria.— In answer 

 to W. H. Groser, I shall be happy to give my ex- 

 perience, having kept reptiles many years. In the 

 first place, my vivarium is an ordinary fern-case, 

 34 in. long, 20 in. deep, 18 in. wide, with a zinc trough 

 at the bottom, 1 1 in. deep, filled with peat-mould ; 

 in the centre a water-tank, which may be formed out 

 of a variety of articles ; for instance, a common gar- 

 den pan, lined with thin cement or well painted 

 outside, simply to keep the water from weeping 

 through ; a glass fern-dish, or, what I consider has 

 a better effect, I have an ornamental terra-cotta pan, 

 12 in. across, and about 3 in. deep, a small rustic 

 ruin in the middle, the top of which is a recess for a 

 small fern. As regards plants, I consider that ferns 

 are decidedly best, as there are so many beautiful 

 forms in the commoner sorts ; for instance, Lastrea 



Filix-mas, Filix-fccniitia, P. angidare, S. vulgarc, 

 B. spicant, and many others, also many mosses ; 

 and one great advantage is, should any of your plants 

 begin to look sickly, you can replace them, the only 

 cost being a pleasurable afternoon's walk in the 

 country lanes, it being a very poor locality where 

 they cannot all be found. I generally trim up mine 

 with a few fresh ferns once a year — not a very hard 

 task. The inhabitants of my case are toads, frogs, 

 salamanders, lizards, &c. For the lizards I have a 

 piece of virgin cork placed in two of the corners, 

 forming imaginary castles, the entire furniture being 

 nice dry moss, which they seem to appreciate amaz- 

 ingly, and soon form their own apartments ; and very 

 pretty it is to see frequently some one or more of my 

 reptile friends sitting, or, if you like it better, lying, 

 with their heads out of the window (that is, holes 

 made by cutting away bits of the cork). Lastly, the 

 food : of course, in summer it is easily procured and 

 various — earth-worms, insects, maggots — a fine food, 

 for those not devoured in the maggoty state will in 

 a short time emerge in the state of large flies, called, 

 when I was a boy, blue-bottles ; and it is wonderful 

 to see the dexterity with which they are caught by 

 the lizards, toads, &c. But in the winter, that is the 

 time — well, it is the time when you can with very 

 little trouble prove that your reptiles are useful as 

 well as, to you, ornamental, by setting traps in the 

 kitchen to catch the cockroaches, that is, supposing 

 you have any ; if not, most likely some of your friends 

 or neighbours have, which no doubt they will very 

 willingly part with. Should that fail, your baker will 

 provide you with any amount for a small cost, to re- 

 pay the boy for catching them. I should have also 

 mentioned that, after watering the ferns occasionally, 

 place a piece of glass over the perforated zinc, to 

 steam and enliven the plants, which the reptiles do 

 not at all object to. — J. IF. Clarke, Park-place, 

 Clifton, Bristol. 



Popular Science. — IXxt Popular Science Rez'ietu 

 well maintains its character in the last issue. Therein 

 we find capital articles by the Rev. W. S, Symonds, 

 F.G.S., on " The Volcanoes of the Haute Loire and 

 the Ardeche " ; on " Flint Implements," by Captain 

 King ; "The Song of the Cicada," by J. C. Galton, 

 F.L.S. ; " Caves and their Occupants," by the Rev. 

 J. M. Mills, F. G. S. ; and one on " Meteorites, and 

 the Origin of Life," by Dr. W, Flight. 



Physiological Tables. — Dr. E. B. Aveling has 

 prepared and published a set of Physiological Tables, 

 whereby a student can see at a glance the various 

 facts in physiology arranged in systematic order. To 

 science teachers this little manual is indispensable. 

 It is published by Hamilton, Adams, «& Co. 



Bournemouth Insects. — During several visits 

 to this watering-place, I have been struck with the 

 remarkable prevalence of the grayling {H. Semele), 

 certainly the commonest butterfly of the neighbour- 



