Dec. 1, 1SG7.] 



HARDWICKE'S SCIEN CE- GOSSIP. 



273 



amount of water introduced into them by the Rhine 

 or Rhone— as, for instance, in Lake Constance or the 

 Lake of Geneva — must make a striking difference. 

 Experiments, however, at these great depths cannot 

 be carried out so easily as many might suppose. A 

 minimum thermometer, for instance, owiug to the 

 pressure of the water, will stand too high. Ordinary 

 thermometers must be protected not] only against 

 compression, but also against the variations which 

 occur while being raised through the water, changes 

 due to the great difference of temperature at the 

 bottom and at the surface of the lake. 

 r Both in Jolly's and Von Schlagintweit's experi- 

 ments precautious are taken, though on totally 

 different principles, against these sources of error. 

 The instruments employed by the latter savant are 

 the same which had already done him good service 

 in the salt lakes of Tibet. 



NEW BRITISH MOSS. 

 (Aidblystegium confervoides. ) 



THIS addition to our moss Elora, we owe to Dr. 

 Eraser, of Wolverhampton, who discovered it 

 on damp stones in Dovedale, in November, 18G6, 

 and having kindly favoured me with specimens, I 

 am enabled to give the accompanying illustrations. 



Fig. 287. Amblysreguim confervoides, 1. Plant, natural size; 



2. Branch, with male flowers and fru t, magnified ; 



3. Capsule, with lid; 4. Perichsetical leaf; 5. Stem leaf. 



The genus Amblystcgium is one of the groups 

 into which Professor Schimper has broken up the 

 heterogeneous collection of species hitherto referred 

 to Hypnum, two other species of which (filicinum 

 and commutatum) might, I think, with propriety 

 be added, and riparium be removed to the aduncum. 

 group. 



We should thus have three sections in the genus.. 



1, Serpentia; 2, Leptodictya; 3, Eilicina. 



The first section would number as European, 

 species. 



A. Sprucci, subtile, tenuissimum, confervoides^ 

 cnerve, serpens, densum, radicale, varium, serru- 

 latum, pinnatum, irriguum, fluviatile. 



Amblystegium confervoides, Schpr. (Hypnum 

 confervoides, Bridel). Monoicous, in dense creeping 

 tufts of a dull green colour, brownish when old, very 

 slender, vaguely branched. Leaves minute distant,, 

 ovato-lanceolate, nerveless, perichsetial lanceolate. 

 Capsule oblong, cernuous. Lid convex with an. 

 oblique point. 



Amblystegium subtile is closely allied, but has a 

 more erect pale capsule, and shorter faintly nerved 

 leaves. 



As it occurs on beech -trees throughout Europe, 

 we may also expect to find it in this country. 



R. Bkaithwaite, M.D., E.L.S. 



SNAKES. 



SCIENCE GOSSIP for November has reiievea 

 ^ me from great embarrassment regarding the 

 account copied into the papers some time since, 

 from the " Liverpool Daily Mercury," entitled " A 

 Rattlesnake at large." I can assure the reader that 

 I almost trembled in my shoes as I thought of the 

 imminent danger I had so often unconsciously in- 

 curred from such peculiarly vicious reptiles ! I have 

 taken great pains in watching and studying the 

 habits of Snakes, the country in which my observa- 

 tions occurred being as prolific in reptiles if not 

 more so than any other on the globe. 



In the tropical forests of Brazil, fostered in the 

 swamps by the hot sun, they spring into life and live 

 for many years. They are also infinitely more active 

 in their movements than those in cooler climates,, 

 and their venom is more powerful ; consequently 

 they have greater powers of offence. But taking 

 all their fatal capabilities into consideration, after 

 a short time resident amongst them, I not only lost 

 all the fear which I originally had of Snakes— and 

 which such tales as that mentioned above served to 

 cultivate in the minds of Londoners and others, 

 who never having seen venomous Serpents in their 

 native state, only know what is related about them — 

 but would spend many an hour wandering in their 

 favourite haunts to capture and preserve them. 



This, you may imagine, brought me into con- 

 tact with not only dangerously strong, but also 

 venomous Serpents. Amongst the latter were in- 

 cluded numerous Rattlesnakes. One, a fine specimen, 

 was seven years old. This I came upon more 

 suddenly than was at all pleasant, as it lay across 

 the footpath asleep ; but fortunately for me t he 

 noise of my approach awoke it, and the rattling 



