94 



SCIENCE-GOSSIP. 



[Apeil 1, 1865. 



A Question fob Ornithologists. — Is there 

 any distinguishable feature in the male young of 

 kites, ravens, or magpies at an early age, so that 

 anyone wishing to rear a male bird might be able to 

 select one without rearing the wliole nestlings for 

 the plumage to determine? If the males can be 

 scientiiically defined, it would save a deal of trouble 

 to many. — Ross. 



Snake-Stones. — We have received several com- 

 munications, but do not think it prudent to occupy 

 more space with this subject; especially as they 

 contain no facts which have not already been pub- 

 lished in "The_ Zoologist," p. 6,983, and Gosse's 

 "Romance of Natural History." — Ed. Sc. G. 



Cleaning Echinus Spines. — Our correspondent 

 (T. K.) says that in rubbing down sections of the 

 spines, by whatever mode it is done, the numerous 

 cells accumulate foreign matters to a considerable 

 extent, and that no one has yet suggested a method 

 by which these sections can be made perfecllp clean. 

 Methods applicable to bone and other equally hard 

 substances, are not necessarily successful in this 

 instance. 



EossiL StiELL.— (In reply to Mrs. D.) The fossil 

 forwarded for identification, obtained from the rail- 

 way-cutting near Evesham, is PJiynchoncUa tetruhs- 

 dra, Sowerby, one of the most characteristic fossils 

 of the zone of Ammonites margitatus, or the marl- 

 stone of the middle lias. — R. T. 



Toads in Town.— Can you or any of your readers 

 inform me whether toads inhabit London houses ? 

 To-day, March 8th, my servant found a full-sized 

 toad in an underground and somewhat damp apart- 

 ment of my house; and he informs me that he found 

 a smaller one in the same place some mouths ago. 

 Jf the toad is an indigenous citizen, on what does 

 he subsist ? Is he in any way injurious ? Where 

 are the ova deposited ? — A. R. 



Garnets.— (In reply to W. M. F. P.)— Garnets 

 occur abundantly in mica slate, hornblende, slate, 

 and gneiss ; somewhat less frequently in granite and 

 granular limestone; sometimes in serpentine and lava. 



AEern Query. — Can you, or any of your readers, 

 explain_ to me ioJiy it is that if a frond of fern is 

 placed in mould for the purpose of rearing seedlings, 

 the young plants produced are not invariably of the 

 same description as the parent frond. Such is my 

 experience, and that of other fern-fanciers who 

 have spoken to me on the subject. — //. /. D. 



Circulation in the Cosmarium.— In last Oc- 

 tober 1 examined some specimens of the Cosmcmum, 

 and was rather surprised to observe a brisk move- 

 ment of particles going on between the two lobes of 

 the plant, very similar to the circulation in the 

 ends of Closterium lunatct, only the movement seemed 

 quicker, and the particles much more numerous and 

 a little larger. I referred to " Carpenter," and other 

 books on Microscopy, but have not yet found any- 

 thing about any movement seen in the Cosmarium. 

 I have often seen this since, and in all cases the en- 

 dochrome has been contracted towards the centre of 

 the lobes, leaving a transparent space between them, 

 in which the circulation took place. I shall be glad 

 to hear whether this has been seen before, or if I 

 may claim the honour of this discovery. — W. H. 

 Holland. ~\^v.x correspondent should have referred 

 to the " Micrographical Dictionary," p. 186, and read 

 as follows : — "A pec\diar swarming motion is ob- 

 servable at times in the cell contents of tliis genus, 

 different from the circulation in Closterium" — lEd. 

 Sc. G.'\ 



Black Cement for Eock-work. — I bought at 

 Covent Garden market a short time since a piece of 

 imitation rock-work made of cinders. I noticed 

 each piece was joined together with a black cement. 

 Can you, or any of your obliging correspondents, 

 tell me how it is made, or where it can be pur- 

 chased ? — Leicester, 



Curious Dietetic Phenomenon. — It is a com- 

 mon custom in the north of Ireland for farmers, 

 whose holdings do not admit of their keeping two 

 horses, to mutually assist by lending to each other 

 alternately, one having the use of his own and his 

 neighbour's horse on one day, while his neighbour 

 lias both on the next. If, before leaving home, one 

 farmer gives his horse a feed of whins {Vlex Euro- 

 p.:cus), which when pounded or beaten is a common 

 article of fodder, while the other feeds his horse on 

 hay or oats, when the horses are put into the 

 plough, tlie one_ that has been fed on the hay or 

 corn becomes quite sick, and only recovers when his 

 fellow is removed from him, or the effects of his- 

 meal pass off. Can any of your readers offer any 

 explanation of this fact ?— i2. 



Mounting Polyzoa. — In reply to a correspon- 

 dent, as to the possibility of preparing specimens of 

 the fresh-water polyzoa, or indeed any of tlie marine 

 zoophytes,_ with the tentacula expanded, as per- 

 manent objects for the microscope, I have found the 

 following raethod, though not uniformly satisfactory, 

 being sometimes rather uncertain in its residts ; yet 

 with patience, and by operating upon a number of 

 slides at the same time, may give, in six cases out 

 of twelve, all that can be desired. Eirst, of the 

 fresh-water species, say Lophoptis ; a portion should 

 be placed in a cell — I prefer those formed by grind- 

 ing out a basin in the slip of glass with a drop of 

 water, and covered with thin glass ; in a few minutes 

 this magnificent creature will expand its glorious 

 horseshoe-shaped head of tentacula, quivering with 

 ciliary action ; then, while it is under the micro- 

 scope, allow a drop ofpure alcohol to run under the 

 cover into the cell ; it instantly causes death, and 

 generally with the tentacula extended ; in many 

 cases excessively so. The cell can then be cemented 

 with Bruusvfick black. But the greater certainty of 

 success is with the marine species, in consequence 

 of the support given by the polypidom. Coryne, 

 for instance, treated with alcohol while in a living 

 state, as I have described, makes a beautiful per- 

 manent object, and illuminated with a_ parabaloid 

 or spotted lens, scarcely inferior to when in its living 

 state. Entromostraca, mounted with alcohol in a 

 similar vfay, scarcely ever fail. — E. D., Crouch End. 



A Dainty Salamander. — " Dytisctis Marginalis" 

 should tempt his pet friend with a fine fat slug. I 

 think it very likely that he finds food to his taste in 

 the moss with which his prison-house is filled, and 

 that he has not absolutely fasted for six months. 

 Insects and slugs are possitly in the habit of visiting 

 the moss-cup. Indeed, I should not be at all asto- 

 nished to hear that he has been sleeping half the 

 time, after the fashion of some of his order, the 

 B/cfoidte family. Tritons have, I understand, a trick 

 of swallowing their own skin ; perchance Mr. Sala- 

 mander has dined on his cast-off suit of clothes, and 

 found them indig^estible ; or may be he took a fancy 

 to a few young relatives in their tadpole state, and, re- 

 penting himself of such a cannibalish trick, is now 

 fasting by way of penance. Aquatic insects and 

 larva; are his natural food, but 1 think he indulges 

 in the freaks above described at times. — .//. ir. 



