92 
NALTORE 
[Vov. 18, 1869 
and if AB be a diameter parallel to 7, 
= PB-PA 
~ PB+PA 
and E, F are complete elliptic functions for modulus c ; 
OP mn @ ie 
also hie BP Nice fe (E-F) 
But av SP 
where w is the solid angle subtended at P by the circle, that is the 
area of the spherical ellipse on a sphere of unit radius cut off 
by the cone whose vertex is P, and base the circle. 
We have expressions for a and ay can aay 
ee dy’ zB 
pressed by elliptic functions, and if so, can V itself be so ex- 
pressed? I am writing out the theory of electric currents in 
also be ex- 
F 1V 
The expression for = for an 
dz 
elliptic disk can be found if we know it for a circular one; for 
the spherical ellipses in the one case are no more complicated 
Can = or V itself, be found for the elliptic 
ax 
which these quantities Occur. 
than in the other. 
disk ?” 
The President and Mr. C. W. Merrifield spoke on the ques- 
tion, but could not decide for or against it impromptu. 
Mr. T. Cotterill then gave an account of his paper on Oppo- 
site Points on a Curve. The subject bore reference to two 
former papers read before the society by the author and by Prof. 
Sylvester, the Theory of Residuals, not yet, to the regret of 
the society, put into a shape for publication. Mr. S. Roberts 
and Mr. W. K. Clifford took part in a discussion upon this 
paper. 
Royal Microscopical Society, November 10.—Rev. J. B. 
Reade, M.A., F.RS., President, in the chair. A communication 
from Dr. Pigott on high power definition with illustrative 
examples was read. The paper had special reference to the 
markings on the Podura scale, of which the writer claimed to 
have discovered the true nature. As the result of close and pro- 
tracted observation, Dr. Pigott believes that he has resolved 
these markings into rows of bead-like bodies essentially differing 
in their character from the ‘‘note of exclamation” markings so 
familiar to microscopists.—Another paper on a cognate subject, 
entitled the Scales of certain Insects of the order Thysanura, was 
read by Mr. S. McIntyre. Mr. McIntyre’s examinations of the 
genus of the family of the Joduride leads him to express conclu- 
sions confirmatory of the views hitherto entertained, as to the 
nature of the markings seen under the microscope ; and in the 
discussion which followed the opinions expressed by the Fellows 
were entirely in support of Mr. McIntyre’s conclusions. Among 
the donations announced was an interesting specimen of an Amici 
reflecting microscope, working on the principle of the Newtonian 
telescope. 
Zoological Society, November 11.—Mr. George Busk, 
F.R.S., V.P., in the chair.—The Secretary made some remarks 
on the more remarkable additions to the Society's Menagerie 
during the past summer, amongst which particular attention was 
called to some Amherst’s pheasants, deposited by J. J. Stone, 
Esq. ; an. Owen’s apteryx, presented by the Acclimatisation 
Society of Otago, New Zealand ; a pair of the newly-discovered 
Chinese deer (Z/aphurus davidianus), presented by Sir Ruther- 
ford Alcock; and a young male Spanish ibex, presented by 
Major Howard Irby.—Extracts were read from a letter addressed 
to Mr. Grote by Dr. John Anderson, C.M.Z.S., containing ob- 
servations respecting the pigmy hog of the Terai (Forcula sal- 
vania), and other animals which he is endeavouring to procure 
for the Society’s Menagerie.—A letter was read from Dr. G, 
Bennett, containing an account of the habits of the wood-hen 
of Lord Howe’s Island, as recently observed by Mr. R. W. 
Fitzgerald.—Mr. Sclater exhibited a specimen of the so-called 
wood-hen, which had been forwarded in spirits by Dr. Bennett 
to the Museum of the Royal College of Surgeons, and stated 
that it was a rail of the genus Ocydromus, apparently hitherto 
undescribed, which he proposed to call Ocydromus sylvestris. — 
A letter was read from Mr. Morton Allport, F.Z.S., containing 
an account of the successful introduction of the salmon trout 
(Salmo trutta) into Tasmania.—Mr. Quelch exhibited a remark- 
able specimen of a fish of the genus Riombus, supposed to be a 
hybrid between the turbot and the brill.—Mr. J. W. Clark, 
F.Z.S., exhibited some mounted skeletons of the extinct dodo of 
the Mauritius, and of the male and female solitaire of the Island 
of Rodriguez, belonging to the Cambridge University Museum. 
—Mr. E. Ward exhibited a curious melanoid variety of the 
woodcock (Scolopax rusticula).— Professor Flower, F.R.S., read 
a memoir on the anatomy of the Aard-wolf (Proteles cristatus), 
founded on a specimen recently deceased in the Society’s Mena- 
gerie. The result arrived at after a careful examination of every 
part of this animal was that Prote/es constituted of itself a dis- 
tinct family of carnivorous animals, allied to the Hyenide and 
Viverride, but more closely to the former than Mr. Flower had 
previously supposed when he had only the skull of this remark- 
able animal to judge by. Mr. Flower’s paper was illustrated by 
the exhibition of the stuffed skin, a complete skeleton, and 
a full series of anatomical preparations of the internal organs 
of this animal, all taken from the same individual.—A com- 
munication was read from Dr. J. G. Gray on the guemul or 
roebuck, from Tinta in Southern Peru, which Dr. Gray considered 
to constitute a new genus of deer, proposed to be called Xenolophus. 
—A second communication from Dr. Gray contained a description 
of Emys laniaria, a new species of fresh-water tortoise, from an 
unknown locality.—A report was read by Dr. A. Giinther on 
two collections of Indian reptiles, recently received by the British 
Museum, one of which had been formed by Dr. Leith in various 
parts of Western India; the second by Mr. Barnes in Ceylon. 
Both were of much interest, and contained various new species, 
which were characterised in the present paper.—A communica- 
tion was read from Dr. B. Simpson, containing notes on the 
habits of Azlurus fulgens, as observed by him during his residence 
in Nepal.—A communication was read from Surgeon Francis 
Day, F.Z.S., containing the first part of a series of notes on the 
specimens of fishes in the Calcutta Museum. Mr. R. B. Sharpe 
read some additional notes on the genus Ceyx, in continuation of 
a former communication on this subject. The principal object ot 
the present paper was to discuss the question of the identification 
of the true Ceyx rfidorsa, Strickland. 
BRIGHTON 
Brighton and Sussex Natural History Society, No- 
vember 8.—Mr. T. H. Hennah, President, in the chair. A rare 
grass, Gastidinm Lendigerum, obtained in October, in the Weald of 
Sussex, by Mr. Davies, was presented by that gentleman. — A paper 
on Mosses was read by Mr. Smith, in which the development, 
growth, mode of reproduction, and the several parts of mosses 
were described and illustrated by enlarged drawings and micro- 
scopic preparations, while it was pointed out that to the micro- 
scopist they opened out fields of research and questions to be 
settled, unsurpassed by any other branch of natural history. 
Prior to reading the paper, Mr. Smith handed in a complete 
Bryological Flora of the county of Sussex, comprising 298 
species and sub-species, a brief account of the soils in which the 
rarer species grow, together with an enumeration of those 
which, at present as regards Britain, have been found only in 
Sussex. This list will be published in the next annual report. 
BRUSSELS 
Royal Academy of Sciences, October 9.—M. Schwann 
reported on the memoir by MM. Masius and Vaulair on the 
anatomical and functional regeneration of the spinal cord, of which 
a notice was given in the last number of NATURE. Besides the 
immediate subject of their memoir, the authors treat of the 
histology of the ft/«m terminale of the spinal cord in the frog, 
and of the cutaneous and medullary distribution of the spinal 
nerves. —M. A. Quetelet communicated notes on the meteors 
observed at Brussels in August, 1869, and on that of the Ist 
October, 1869 ; and M. Terby noticed the meteors observed at 
