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HARDWICKE'S SCIENCE-GOSSIP. 



ZOOLOGY. 



Destruction of the Phylloxera. — M. Pasteur 

 has recently suggested that the destruction of the 

 Phylloxera might be accomplished by inoculation 

 ■with some microscopic fungus, and the Academy 

 of Sciences, Paris, have invited the attention of 

 naturalists to this subject. 



A Natural History Society for the Isle 

 ■OF Man. — We are glad to see that an attempt is 

 •being made to organise a natural history society in 

 the Isle of Man. A nucleus has already been formed, 

 with Mr. E. Birchall, F.L.S., the well-known ento- 

 mologist, as President. There is no better British 

 locality for the pursuit of natural history generally 

 than this little island, so well known to naturalists 

 as the birth-place of Professor Edward Forbes. 



The Deal-Fish.— We have been informed by a 

 correspondent that a specimen of the deal-fish 

 (Trachyptems arcticus), the occurrence of which on 

 the Norfolk coast we noticed in our February number, 

 has been obtained near Whitby. The specimen, 

 which was left by the tide among the rocks, was 

 about 1 6 feet long. Dr. Fleming describes several 

 which were cast up at Sanda, Orkney ; they were 

 about 3 feet to 4J feet in length. These fish are very 

 rare, keeping out in deep water ; they only approach 

 the shore in Iceland, where the bottom is sandy, and 

 not steep. The deal-fish are provided with ventral 

 fins (contrary to the old opinion), but these are very 

 delicate, and when the fish is captured they are 

 usually destroyed. Their absence, from this cause, led 

 naturalists for a long time to imagine the ventral fins 

 were wanting. The body is compressed, or sword- 

 blade-like throughout more than half of its own 

 length. There are two species of this genus found in 

 the Mediterranean. 



Skin Preserving.— In the paper on this subject, 

 published last month, for "arms" (p. 54, col. 1, 

 par. 3, line 5 ; and par. 4, line 1,) read "anus," and 

 for " back " (p. 54, col. 2, par. 3, line 4), read 

 "beak." 



The Needle-tailed Swift. — Mr. G. B. Corbin 

 in the " Zoologist," reports that a specimen of 

 this rare bird was shot in Hampshire, July 27, 1879. 

 This is only the second time that it has been found 

 in Western Europe ; the first time it was also seen in 

 England, at Great Horkesley, near Colchester, in 

 July 1846. 



Air-bladders in Fish. — A paper on this subject 

 has been read before the Cotteswold Naturalists' 

 Field Club, by Mr. Francis Day, F.L.S., F.Z.S. 

 Mr. Day remarks that few among the organs in 

 fishes have been the cause of so much discussion as the 

 air-bladder, which is a single or variously divided sac, 



situated beneath the vertebral column and the kidneys, 

 and placed above the centre of gravity. As the air- 

 bladder is sometimes present or absent in species of 

 the same genus, it is evident it is not entirely indis- 

 pensable to the fish's existence. It originates as an 

 offshoot from the stomach, which offshoot elongates 

 and then enlarges at its extremity into what is termed 

 the air-bladder. In the Dipnoids the air-bladder 

 communicates with the oesophagus during life, and 

 the functions of the air-bladder are analogous to those 

 of lungs. In Amia, a ganoid fish, it has also a lung- 

 like function, but in Acipenser it is used merely for 

 hydrostatic purposes. The air-bladders, however, are 

 not considered as lungs in most fishes, since the blood 

 is supplied to them from the adjacent arteries, and in 

 many cases returns as venous blood into the circula- 

 tion. In Lepidosiren, however, in consequence of the 

 non-development of gills on the two inferior branchial 

 arches, the blood is not arterialised there, but passes 

 0:1 to the air-bladder for this purpose. The Lepido- 

 sirens doubtless are the highest known form of living 

 fish, forming a transitional link between amphibia 

 and fishes. The chief use of the air-bladder in 

 Teleostean fishes is : (1) Hydrostatic ; (2) Acoustic ; it 

 being partially, or entirely, employed for hearing by 

 means of various modes of connection with the 

 internal ear. In the Physoclisti or Physostomi the air- 

 bladder occurs as a closed sac. In the marine forms 

 of these orders, a tubular prolongation itself passes 

 forward to the anterior portion of the skull to 

 establish an auditory communication, but in the 

 freshwater species the connection is formed by a 

 chain of auditory ossicles. In conclusion, Mr. Francis 

 Day says the air-bladder in fishes is the homologue 

 of the lung of the superior vertebrate forms, and 

 that in some of the higher sub-classes it serves as an 

 accessory respiratory organ. 



BOTANY. 



Respiration of Plants. — I have been somewhat 

 bewildered by a paragraph on the above subject which 

 I have met with in Sach's "Text-Book of Botany," 

 and which upsets all my preconceived notions on the 

 subject. The paragraph in question will be found at 

 page 644 of the English edition, and runs as follows : 

 " The respiration of plants consists, as in animals, in 

 the continual absorption of atmospheric oxygen into 

 the tissues, where it causes oxidation of the assimi- 

 lated substances, and other chemical changes result- 

 ing from this. The formation and exhalation of 

 carbon dioxide — the carbon resulting from the de- 

 composition of organic compounds — may always be 

 directly observed ; the production of water at the 

 expense of the organic substance in consequence of 

 the process of respiration is inferred from a com- 

 parison of the analysis of germinating seeds with the 

 composition of those which have not yet germinated. 



