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HARDWICKE'S SCIENCE-GOSSIP. 



manipulation in my hands, it is desirable that com- 

 petent mounters should try it and report results. To 

 draw attention to it is my object in writing. — A. P. 

 Wire. 



Crystals for the Polariscope. — If Mr. J. W. 

 Neville uses castor oil to mount crystals in, he will 

 not be troubled any longer by the unpleasant results 

 described by him. — Charles F. IV. T. Williams, B.A. 



Parasites of Birds, &c. — Mr. C. Collins has for- 

 warded specimens of a new series of his " special " 

 micro-slides ; a series of parasites chiefly of birds. 

 Those sent are the parasites of heron, gull, and 

 penguin, each slide being furnished with a label 

 giving the classification, from sub-kingdom down to 

 species. 



Royal Microscopical Society. — The Journal 

 for April contains, besides the summary of current 

 researches, the president's address on septic organ- 

 isms, "The Lantern Microscope," by Mr. Lewis 

 Wright ; "On some unusual Forms of Lactic Fer- 

 ment — Bacterium lactis," by Dr. R. L. Maddox ; and 

 a paper on a " Cata-dioptric Immersion Illuminator," 

 by Mr. J. Ware Stephenson. 



ZOOLOGY. 



In the recent issue of the Proceedings of the 

 Zoological Society of London is an interesting paper 

 by 1 Mr. II. Pryer, giving an account of a visit to the 

 Birds'-nest Caves of British North Borneo, his object 

 being to ascertain from what substance the edible 

 nests, so much prized in China, are made. Large 

 caves in Limestone rocks are inhabited both by 

 b ats and by the swifts, which build the nests in 

 question, the nests being attached to the roof or walls 

 of the caves. Mr. Pryer says that the material of 

 which they are made may be found encrusting the 

 rock in damp places, and resembling half-melted gum- 

 tragacanth. The account of the departure of the bats 

 and the return to roost of the swifts is worth quoting. 

 " Soon I heard a rushing sound, and, peering over 

 the edge of the circular opening leading into Simud 

 Itam [or the Black Cavern], I saw columns of bats 

 wheeling round the sides in regular order. Shortly 

 after five o'clock, although the sun had not yet set, the 

 columns began to rise above the edge, still in a 

 circular flight ; they then rose, wheeling round a high 

 tree growing on the opposite side, and every few 

 minutes a large flight would break off and, after 

 rising high in the air, disappear in the distance ; each 

 flight contained many thousands. I counted nineteen 

 flocks go off in this way, and they continued to go off 

 in a continual stream until it was too dark for me to 

 see them any longer. ... At a quarter to six the 

 swifts began to come in to Simud Putih [the White 

 Cave] ; a few had been flying in and out all day long, 



but now they began to pour in, at first in tens and 

 then in hundreds, until the sound of their wings was 

 like a strong gale of wind whistling through the 

 rigging of a ship. They continued flying in until 

 after midnight, as I could still see them flashing by 

 over my head when I went to sleep. . . . Arising 

 before daylight, I witnessed a reversal of the proceed- 

 ings of the previous night, the swifts now going out 

 of Simud Putih, and the bats going into Simud Itam. 

 The latter literally ' rained ' into their chasm for two 

 hours after daylight. On looking up, the air seemed 

 filled with small specks, which flashed down perpen- 

 dicularly with great rapidity and disappeared in the 

 darkness below." The swift has been determined to 

 be Collocalia fiuiphaga, the alga a species, probably 

 new, of Glceoeapsa, and the bat, Nyctinomus plicatus. 

 There is an abundant supply of guano in these caves. 



Rana esculenta. — This frog, commonly con- 

 sidered to occur only on the continent, has been 

 found in Norfolk. It appears that forty years ago or 

 more, Mr. G. Berney turned some out in that county, 

 and it is considered by Mr. G. A. Boulenger, F.Z.S., 

 that the specimens captured are their descendants. 



Succinea Pfeifferi, var. parvula. — I have 

 recently found some Succineoe at Barnes, one of which 

 I sent to Mrs. Fitzgerald, of Folkestone, and which 

 she determined as belonging to the above form. I 

 have recently taken on Barnes Common, with the 

 Succinea, Limax Levis and Hyalina fulva, and a 

 little way off, on a grassy bank, a specimen of 

 Cochlicopa lubrica, which Messrs. Taylor and Roebuck 

 have identified as var. minima, Siem. — T. D. A. 

 Cockerell. 



V arieties of Arion ater. — Mr. Elliot has sent 

 me some specimens of the variety bicolor, which he 

 finds in damp places near Stroud. It certainly is a 

 very fine form, being rather related to the var. 

 albo-latcralis ^ol Roebuck. As a good deal of con- 

 fusion seems to prevail concerning the varieties of 

 A. ater, perhaps it may be well to give a brief de- 

 scription of the various forms, as I understand them. 

 I. Type form. Entirely black. 2. var. marginata. 

 Black, with an orange or reddish foot-fringe. 3. var. 

 nigrescens. Dark grey, with the sides usually rather 

 lighter : var. plumbea, Roebuck ; lead colour, seems 

 to be very nearly allied to this if the two can well 

 be separated. 4. vzx.rufa. Reddish or brownish. 

 5. var. succinea. Yellow or yellowish ; var. palles- 

 cens of Roebuck is light yellow. Perhaps it 

 would be better to call both these yellow varieties 

 succinea. 6. var. albida. White. 7. var. bicolor. 

 Back brown, sides primrose yellow, foot-fringe 

 orange. The brown of the back is sharply defined 

 from ths yellow of the sides. 8. var. albo-lateralis. 

 Back black, sides white, the two colours sharply 

 defined as in bicolor, foot-fringe orange. This 

 variety has been found in Carnarvonshire and in 

 West Sussex. Mr. Elliot's variety, with the inter- 



