164 



NA TURE 



[December 17, 1891 



That for a temperature of 200° C. the value of d in the 

 formula 



e = 0-00IIII3 + o-oi43028(/-^ 



must be something like 244 mils, or 6*2 mm., in order that the 

 neglect of the second term may not make an error in ^.of more 

 than 5 per cent., and something like i"28 inches, or 32 "5 mm., 

 if the error is not to exceed i per cent. 



And that for a temperature of 300° C. the value of d in the 

 formula 



e = 0-0011353 + o"oi6o84d'"^ 



must be something like 267 mils, or 6*8 mm., in order that the 

 neglect of the second term may not make an error in e of more 

 than 5 per cent., and something like 1*39 inches, or 35*3 mm., 

 if the error is not to exceed I per cent. 



Generally, then, we may conclude that to assume that the 

 emissivity is a constant for wires whose diameters vary from a 

 small value up to i inch is to make a large error in the case of 

 the greater number of the wires, and an error of hundreds per 

 cent, in the case of some of them. 



Using the formula (3) which we have arrived at for deter- 

 mining the emissivity of platinum wires of diflerent diameters at 

 300° C., it follows that to maintain a platinum wire 0*75 mil in 

 diameter at 300° C. would require a current density of 331,000 

 amperes per square inch ;. and, if the emissivity of a copper wire 

 of the same diameter and at the same temperature may be taken 

 as being the same, it follows that to maintain a copper wire 

 075 mil in diameter at 300° C. would require a current density 

 of 790,000 amperes per square inch. 



November 26, — " A New Mode of Respiration in the 

 Myriapoda." By F. G. Sinclair (formerly F. G. Heathcote), 

 M.A., Fellow of the Cambridge Philosophical Society. 



The Scutigeridse respire by means of a series of organs arranged 

 in the middle dorsal line at the posterior edge of every dorsal 

 scale except the last. 



Each organ consists of a slit bounded by four curved ridges, 

 two at the edges of the slit, and two external to the latter. The 

 slit leads into an air sac. From the sac a number of tubes are 

 given off ; these tubes are arranged in two semicircular masses. 

 The ends of the tubes project into the pericardium in such a 

 manner that the ends are bathed in the blood and aerate it just 

 before it is returned into the heart by means of the ostia. In 

 the living animal the blood can be seen through the transparent 

 chitin of the dorsal surface surrounding the ends of the tubes ; 

 and in the organ and surrounding tissues cut out of a Scutigera 

 directly it is killed the blood corpuscles can be seen clustering 

 round the tube ends. If the mass of tubes of a freshly killed 

 specimen are teased out under the microscope in glycerine, they 

 can be seen to be filled with air. The tubes each branch several 

 times. Each tube is lined with chitin, which is a continuation 

 of the chitin of the exo-skeleton. Each tube is also clothed 

 with cells, which are a continuation of the hypodermis. The 

 tubes end in a blunt point of very delicate chitin. 



I therefore hold that the respiratory organ in Scutigera holds 

 a position intermediate between the tracheae of Myriapods and 

 the lungs of Spiders. I hold w ith A. Leuckart (Zeitsch.fiir IViss. 

 Zool., vol. i. p. 246, 1849, "Ueber den Bau und Bedeutung der 

 sog. Lungen bei den Arachniden") that the tracheae have 

 developed into the lungs of Spiders and Scorpions, and I think 

 that the organs in question form a series of which the lowest 

 term are the tracheae, the next the organ of Scutigera, then the 

 lungs of Spiders, and then of Scorpions. 



Zoological Society, November 17. — Dr. A. Giinther, 

 F.R.S., Vice-President, in the chair. — The Secretary read a 

 report on the additions that had been made to the Society's 

 Menagerie during the month of October 1891, and called special 

 attention to the following : a young Buffon's Skua {Stercorarius 

 parasiticus), captured near Christchurch, Hampshire, and pre- 

 sented by Mr. E. Hart, and a Land-Crab {Geocarcimis rtiricola) 

 from the island of Fernando de Noronha, brought home and 

 presented by Mr. D. Wilson-Barker. — The Secretary read a 

 letter from Dr. G. Martorelli, of Milan, inclosing a coloured 

 drawing of both sexes of a hybrid Duck bred in the public Garden 

 of Milan, between Branta rufina i and Anas boschas 9 . — 

 Mr. G. A. Boulenger gave an account [of the various forms of 

 the Tadpoles of the European Batrachians, and a statement of 

 the characters by v\ hich the different species may be distinguished 

 in this stage of their existence. — A communication was read from 



NO. II 55, VOL. 45] 



Mr. Edgar A. Smith, containing descriptions of new species of 

 Shells from New South Wales, New Guinea, and the Caroline 

 and Solomon Islands, based on specimens lately presented to 

 the British Museum by Mr. John Brazier, of Sydney. — Lord 

 Walsingham gave an account of the Microlepidoptera of the 

 West Indies, based primarily on the collections made in St. 

 Vincent and other islands by Mr. H, H. Smith, under the 

 direction of the joint Committee of the British Association and 

 the Royal Society for the exploration of the Lesser Antilles, — A 

 communication was read from M. E. Simon containing the first 

 portion of an account of the Spiders of the island of St. 

 Vincent, based on specimens obtained under the direction of 

 the same Committee. — A communication was read from Mr. H. 

 Nevill, urging the importance of founding an experimental 

 Zoological Station in the tropics, and advocating the claims of 

 Trincomalee in Ceylon for such an institution. — Dr. Johnson 

 Symington read a paper on the nose, the organ of Jacobson, 

 and the dumb-bell shaped bone in the Ornithorhychus. — Mr. A. 

 Smith- Woodward read a paper on a Mammalian tooth from the 

 Wealden formation of Hastings, being the first trace of a 

 Cretaceous Mammal discovered in Europe. This remarkable 

 fossil the author was inclined to refer provisionally to the genus 

 Plagiaulax of the Purbeck Beds, and to call Plagiaulax daivsoni, 

 after its discoverer. — A communication was received from Mr. C. 

 Davies Sherborne, giving an exact account of the dates of issue 

 of the parts, plates, and text of Schreber's " Saugethiere." 

 Great difficulties in synonymy had arisen from previously im- 

 perfect knowledge of these dates. 



December i. — Mr. Henry Seebohm in the chair.— Mr. 

 Sclater exhibited a specimen of a Shearwater obtained near 

 Sydney, and brought from Australia by Prof Anderson 

 Stuart. This specimen had been determined by Mr. Salvin 

 to belong to Ptiffinus gavia, a New Zealand species not 

 hitherto known to occur in Australia. —Mr. Seebohm exhibited 

 and made remarks on specimens of several very interesting birds 

 recently obtained in Ireland. Amongst these was an example 

 of" the Yellow-browed Warbler {Phylloscoptis siiperciliosus) 

 obtained on the Tearaght Rock, the most westerly station in 

 Europe. — Dr. E. Hamilton exhibited a specimen of the Red- 

 breasted Snipe of North America {Macrorhamphus griseus), 

 obtained in Scotland. — Mr. W. B. Tegetmeier exhibited some 

 specimens illustrative of the abnormal form of the bill in birds 

 caused by injuries to that organ during life. — Mr. G. A. 

 Boulenger read some notes on specimens of Reptiles from 

 Transcaspia recently received by the British Museum, and 

 pointed out that examples of several well-known Indian species 

 occurred in this collection. — A communication was read from 

 Miss E. M. Sharpe containing the second portion of her de- 

 scriptions of new Butterflies trom British East Africa, collected 

 by Mr. F. J. Jackson during his recent expedition. — Mr. A. D. 

 Michael read a paper upon the association which he had 

 observed between certain Acarines of the family Gamasidae and 

 certain species of Ants. The author came to the following con- 

 clusions : (i) that there is an association between some 

 Gamasids and Ants ; (2) that a species of Gamasid usually 

 associates with one or two species of Ant preferentially ; (3) 

 that the Gamasids of Ants'-nests are not usually found else- 

 where ; (4) that the Gamasid abandons the nest if the Ant does ;. 



(5) that the Gamasids live upon friendly terms with the Ants ; 



(6) that the Gamasids are not true parasites ; (7) that they do 

 not injure the Ants or their young ; (8) that the Gamasids will 

 eat dead Ants, and are probably either scavengers or messmates. 

 — A communication was read from Mr. Edward Bartlett con- 

 taining an account of the specimens of Rhinoceros from Borneo 

 contained in the Museum of Sarawak. — A communication was 

 read from Mr. T. T. Somerville, of Christiania, containing note& 

 on the Lemming {Myodes lemmus). 



AnthropologicalInstitute,November24. — E. W. Brabrook 

 Vice-President, in the chair. — A paper on the perforated stones of 

 South Africa, by H. Mitford Barber, was read. — An account of the 

 Similkameen Indians of British Columbia, by Mrs. S. S. Allison, 

 was read, The tribe at present inhabiting the upper valley of the 

 Similkameen are immediately descended from a small band of 

 the warlike Chilcotins, who established themselves in the upper 

 valley of the river about a hundred and fifty years ago, and 

 intermarried with the Spokans. They have much deteriorated,, 

 both physically and mentally, within the last twenty years, and 

 are rapidly becoming extinct. The average stature of the men 

 is about 5 feet 6 inches ; their frames are lithe and muscular 



