Dec. 28, 1882 | 
NATURE 
2a5 
as 574 per 1000! Maine and Normandy, notwithstanding their 
natural productiveness, are conspicuous for the regular diminu- 
tion of their populations.—On a new form of sclerosis of the 
cerebral convolutions, by M. Pozzi, with special reference to the 
cerebral lesions common in insanity.—M. Duval’s demand, ia 
the name of a large number of his confréres, for the foundation 
by the Society of an annual Darwinian Conference, was 
opposed by M. Mortillet in as far as the term Darwinian 
was concerned, which he proposes to replace by that of 
transjormist, arguing that the adoption of the word “ Dar- 
winism” is an act of injustice to Lamarck, whose researches 
entitle him to be regarded as the father of transformism. 
Tbe question has been referred to the Central Committee, 
—M. Topinard’s explanation of the funereal objects col- 
lected in the Philippines by M. Marche’s mission.—A discus- 
sion on the project for a general manual of ethnographic ques- 
tions, as drawn up by M. Letourneau for the Society. The plan 
followed, which is that adopted by the Florentine Society of 
Anthropology, is criticised at great length by M. Dally, who 
strongly objects to the phraseology and definitions employed in 
the questions, and in consequence of his objections M. Letour- 
neau’s proposed ‘‘ Questionnaire ” has been referred to a special 
commission for further consideratior. 
SOCIETIES AND ACADEMIES 
LoNnDON 
Royal Society, December 14.—Note on a discovery, as yet 
unpublished, by the late Prof. F. M. Balfour, concerning the 
existence of a Blastopore, and on the origin of the Mesoblast in 
the embryo of Perifatus capensis, by Prof. Moseley, F.R.S., 
and Adam Sedgwick, M.A., Fellow of Trinity College, Cam- 
bridge. 
The late Professor Balfour was just before his death engaged 
on the preparation of a monograph on the anatomy and develop- 
ment of the members of the genus Peripatus, together with an 
account of all known species. He left a series of notes, com- 
pleted MSS., and drawings, which will be edited by the above 
authors, and issued shortly in the Quarterly Fournal of Micro- 
scopical Science. His discoveries, however, concerning the early 
embryology of ?. capensis are so remarkable that the above pre- 
liminary note has been communicated at once to the Royal 
Society. 
The discovery is shortly as follows :—That a widely open slit- 
like blastopore is formed in the early oval embryo of Peripatus, 
which blastopore, occupying the median ventral line, becomes 
closed in its centre an anterior portion remaining open as the 
mouth, whilst a posterior portion apparently becomes the anus. 
The mesoblast is formed from the hypoblast at the lips of the 
blasotopre, and makes its appearance as a series of paired hollow 
outgrowths from the cavity of the archenteron. This most 
primitive method of the the formation of the mesoblastic somites 
closely similar to that occurring in Amphioxus and other ancestral 
forms, is of the greatest morphological significance, and it is 
especially interesting to find that it survives in an entirely unmodi- 
fied condition in Peripatus, the adult organisation of which proves 
that it isa representative of an animal stock of the most remote 
antiquity. 
Mr. Sedgwick, by examining some embryos in Prof. Balfour’s 
collection of material as yet uninvestigated, has been able to con- 
form his results, and also by finding earlier stages to verify certain 
points in the developmental history which rested at the stage at 
which Prof. Balfour's inquiry ceased, mainly on inference. A dis- 
cussion took place, in which Prof. Huxley, Prof. Lankester, and 
Mr. A.Sedgwick took part. The latter pointed out the close 
resemblance of the early embryo Peripatus with open blastopore 
to an actinia, the mesoblastic pouches corresponding to inter- 
mesenterial cavities, and the blastopore to the mouth, and urged 
that the discovery tended to confirm Prof, Balfour’s published 
theory as to the origin of the’bilateralia from the elongation trans- 
versely of a disc-like ancestor, the ventral nerve-cords having 
been formed by the pulling out into long loops of a circum-oral 
ring. 
Prof. Lankester expressed his opinion that the view that the blas- 
topore represented astructure, which in an ancestral form acted as a 
mouth, must be abandoned. ‘The blastopore is very probably 
merely an aperture necessarily formed in the process of produc- 
tion of the hypoblast by invagination, and has never had any 
special function. Prof, Huxley pointed out the essential differ- 
ence between the peripheral nerve ring of Hydromedusze and 
a true circumoral nerve ring. 
Geological Society, December 6.—J. W. Hulke, F.R.S., 
president, in the chair.—Charles Bird, Enoch Cartwright, Henry 
Eunson, William Johnstone, Henry Liversidge, Henry George 
Lyons, Joseph Mawson, Horace W. Monckton, Henry Alexan- 
der Miers, John Postlethwaite, and Thomas Viccars, were elected 
Fellows of the Society.—The following communications were 
read :—Note on a Wealden fern, Oleandridium (Taniopterts) 
Beyrichii, Schenk, new to Britain, by John E. H. Peyton, 
F.G.S.—On the mechanics of glaciers, more especially with 
relation to their supposed power of excava ion, by the Rev. A. 
Irving, F.G.S. Generally, the author concluded, from mecha- 
nical and physical considerations, that far too much erosive 
power has been attributed by some writers to glaciers, and that 
it is doubtful if the work of actual excavation has been accom- 
plished by them at all. The differential movement of glaciers 
he attributed to three causes : (1) cracking and regelation (Tyn- 
dall and Helmholtz) ; (2) generation of heat by friction within 
the glacier (Helmholtz) ; (3) the penetration of the glacier by 
luminous solar energy, the absorption of this by opaque bodies 
contained in the ice (stones, earth, organic germs, &c.), and the 
transformation of it in this way into eat. To this last he 
attributed the greater differential movement of the glacier (a) by 
day than by night, (4) in summer than in winter. 
Physical Society, December 9.—Prof, Clifton, president, 
in the chair.—New members: Mr. H. E. Harrison, B.Sc., 
Mr. S. T. H. Saunders, M.A.—Prof. G. Forbes read a paper 
on the velocity of light of different colours. The author con- 
cluded from his experiments described to the Society a year ago, 
that blue rays travel quicker than red rays. M. Cornu had 
endeavoured to explain this result by peculiarities of the appa- 
ratus employed ; but this explanation seemed doubtful. It was 
suggested that the experiments might be repeated with such 
modifications of the apparatus as would set the question at rest. 
—Professors Ayrton and Perry read a paper on the resistance of 
the voltaic arc, or the opposition electromotive forces set up. 
The electromotive force was measured by a voltmeter con- 
nected between the terminals of the lamp. Keeping the width 
of are coastant the E.M.F. was found to diminish as the current 
increased. Keeping the current constant, the E.M.F. increased 
rapidly, at first with an increasing width of arc, and afterwards 
more slowly. The authors gave a curve representing the change. 
About 80 volts are required to produce an arc of one-third 
of an inch. For further increase of arc E.M.F. is therefore 
proportional to increase of length of arc. The authors also 
read a paper on the relative intensities of the magnetic 
field produced by electromagnets when the current, iron core, 
and length of wire, &c., are constant, but the wire differently 
distributed. In a case the wire was wound uniformly from end 
to end; in J case it was wound from the middle to one end ; in 
¢ case it was wound only at both ends ; ind case it was wound 
only at one end, The field was measured along a line running 
through the axis of the poles beyond the magnet of the above 
plans; a@ gave the strongest field, except at short distances, 
when 4 was best.—Professors Ayrton and Perry also exhibited a 
set of three Faure accumulators in series feeding twenty Swan 
lamps, each lamp giving over 1 candle power. The electro- 
motive force of each cell vas about 2 volts. 
Anthropological Institute, December 12.—Mr. M, J. Wo!- 
house, F.R.A.S., in the chair.—Mr. A. L. Lewis exhibited 
some Neolithic flint implements and flakes found by him at 
Cape Blanc Nez, near Calais.—A paper by Mr. A. W. Howitt, 
F.G.S., on the Australian class systems, was read, in which the 
author discussed and explained the various rules with respect to 
marriage adopted by several of the native tribes. 
SYDNEY 
Linnean Society of New South Wales, September 27.— 
Dr. James C. Cox, F.L.S., &c., in the chair.—The following 
papers were read:—On a resinous plant from the interior, by 
K. H. Bennett. Specimens of the gum or resin of this plant, 
which Mr. Bennett described as ALyoporum platycarpum, R. Br., 
were exhibited.—On three new fishes from Queensland, by 
Charles W. De Vis, B.A. This paper was a description of a 
new genus of the family Berycide, and a species of Homalogrystes 
and Scolopsis.—Contribution to a knowledge of the fishes of 
New Guinea, No. 2, by William Macleay, F.L.S., &c. This 
is a continuation of a list of the fishes found at Port Moresby by 
