posing the ring, that the velocity of the resulting rotation must 
Be cock as is actually observed in the case of the planets 
referred to, whose mass represents nine-tenths of the whole 
planetary system. 
In Jupiter and Saturn, the velocity of a particle in the 
_ planet is very nearly the velocity of the planet itself. Then 
Jupiter and Saturn must have derived their material from the 
whole mass of the planetary system. The best theories of the 
earth make it of uniformly decreasing density from the surface 
to the centre. Suppose that after Jupiter were formed it were 
_ condensed, that might otherwise explain its velocity. He showed 
that, in the case of the planets, the velocity, had it been 
one-half what it actually was, would have resulted in their 
having no rotation. This theory was applied to the absence 
_ of rotation in the case of our satellite. He showed the pro- 
bability that the original nebular ring from’ which the planets 
_ were formed may have been of twice the size of their present 
orbits. The nebular theory, to meet the requirements of the 
| mere mathematician, would have placed all the planets at regu- 
_ lar distances, and given them exactly similar motion, But not 
such was the method of nature. 
In the discussion which followed he stated that we have never 
seen anything of Jupiter or Saturn but the clouds which cover 
them. He thought that those planets were yet at a white heat, 
_ and we simply saw the clouds that are raining down upon them. 
The present state of the satellites may be a result of their tides, 
and not the index of their original velocity. Jupiter and Saturn 
_ took so large a proportion of all the planet-forming material 
_ that the laws impressed upon them may serve best to tell the 
_ whole history of the solar system. There may be, however, a 
rotation of the inner mass of those planets of which we know 
nothing. 
Geology of Southern New Brunswick. By Prof. T. Sterry 
 Hunt.—The recent labours under the Geological Survey of 
Canada, by Messrs, Bailey Matthew and the author, were 
sketched. They show south and west of the coal basin various 
uncrystalline formations, all resting upon ancient crystalline 
rocks. ‘These latter are by the author regarded as for the most 
part the equivalents of the Green Mountain and the White 
Mountain series, or what he calls Hurordan and Montalban. 
These are penetrated by granites, and associated in one part with 
Norian rocks, but the presence of Lamentranis somewhat doubt- 
ful. While the author recognises thus, at least, four distinct 
“series of pre-Cambrian crystalline rocks in Eastern North Ame- 
rica, he does not question the possible existence of yet other 
Series in this region. The analogies offered by the more recent 
rocks of this region are very suggestive. 
On the Possibility that the Sun, while mainly Gaseous, may have 
a Liquid Crust. 
very little doubt that Secchi and others, who hold that the sun 
is mainly gaseous, are correct in this: the smallness of density 
cannot possibly be explained on any other supposition. At the 
same time the eruptional phenomena which are all the time oc- 
curring on the surface, almost compel the supposition that there 
isa crust of some kind which restrains the imprisoned gases, 
and through which they force their way in jets with great 
violence. . j 
Prof. Young suggesis that this crust may consist of a more or 
- less continuous sheet of descending rain, not of water, of course, 
but of the materials whose vapours exist in the solar atmosphere, 
and whose condensation and combinations are supposed to fur- 
nish the solar heat. As this tremendous rain descends, the 
velocity of the falling drops would be retarded by the resistance 
of the denser gases underneath ; the drops would coalesce until 
a continuous sheet would be formed ; and these sheets would 
unite and form a sort of bottomless ocean resting upon the com 
pressed vapours beneath, and pierced by innumerable ascendir 
jets and bubbles. It would have an approximately cons‘a ut 
depth in thickness, because it would re-evaporate at the bom 
nearly as rapidly as it would grow by the descending rains above, 
though probably the thickness of this sheet would continually in- 
crease at some slow rate, and its whole diameter diminish. 
Prof. Young added an explanation of the narrow disc fringes 
seen at the moment of totality in a total eclipse, showing them 
to be optical interference effects caused by the sudden changes of 
the temperature of the air at the edge of the shadow. The 
twinkling of stars is analogous in many respects. 
The Existence of Live Mammoths. By Prof. Feuchtwanger.— 
The discovery of the mammoths in Siberia in the deep gorges of 
the mountains near the Lena Viner, which was lately published 
as having been made by a scientific Russian convict, who 
By Prof. Charles A. Young.—There can be | 
NATURE 
five living animals, twelve feet in height and eighteen feet in 
length, with projecting tusks four feet long, excites some dis- 
cussion in Europe. I think it worthy of inquiry whether the 
mammoth of the past terliary period, discovered during this cen- 
tury in Siberia, near the same river, can have any relation to the 
convict’s discovery. Thousands of these animals have been 
found buried in the ice, with their well-preserved skins, and 
thousands of tusks are brought to England to this day for the use 
of the turner. These are of nearly the same dimensions as those 
seen by the Russian, The convict has received an unconditional 
pardon, on the recommendation of scientific men who have in- 
vestigated his statements and believe them to be true. 
_ Prof. E. S. Morse, of Salem, Mass., read a paper on the sub- 
ject of Variations in Wave Lengths. Prof. Morse first called 
attention to the interesting discoveries of Lockyer, Huggins, and 
others in accounting for the displacement of lines in the spectrum _ 
in observations of celestial objects. It is well known that when 
a star is approaching the observer the luminiferous waves emitted 
by it are crowded together, and on the contrary are separated 
when the star is receding. 
Mr. Morse brought forward an instrument by which this 
phenomenon in the case of light may be easily and plainly illus- 
trated before a large audience. The instrument consists of a 
tank filled with water and set on wheels. Onthetop of thisis a 
compartment containing compressed air. From one end of the 
tank a pipe protrudes, which is moved up and down at a fixed 
rate by simple clockwork. When the cock is opened, allowing 
the water to escape from the pipe, the stream assumes a sinuous 
line, which may be shown, if brilliantly lighted, across a large 
audience hall. This undulatory stream, when the tank is at rest, 
illustrates a luminiferous wave from a stationary source. To 
exhibit the shortening or lengthening of the waves of light by the 
approach or recession of the luminiferous body, Mr. Morse simply 
moves the apparatus rapidly back and forth on the table. As 
the apparatus moves with the direction of the stream its undu- 
lations are crowded together, and the waves are consequently 
shortened. On the other hand, when the motion of the appa- 
ratus is in an opposite direction, the waves are proportionably 
lengthened. The advantage of this illustration is that it exhibits 
precisely what takes place in the luminiferous waves approaching 
or receding from the observer of celestial bodies, producing the 
displacement of spectrum lines. 
Concerning Hyalonema. By Dr. Samuel Lockwood.—The 
recent deep-sea dredgings have done much toward clearing up the 
singularly anomalous history of the Japanese glass-rope sponge. 
Prof. Lockwood, however, thinks that, either from inapprecia- 
tion or otherwise, the knowledge thus obtained has not been 
applied to the elucidation of certain mooted points connected 
with Hyalonema. With regard to the mistakes in representing 
Hyalonema “ wrong end up,” my opinion is that the error was 
led off by the Japanese themselves. The drawings by the native 
artists represented these curious objects as attached to the sea 
bottom by the sponge mass, thus making the fascicle to be erect 
and uppermost. Obtained by the net, or some such means, from 
the bottom at great depths, it is supposable that the fishermen 
at Enoserma were entirely ignorant of the matter. Their theory, 
however, as represented by the native artists, has wrongly repre- 
sented the Hyalonema, These ropes attached to the sponge and 
sand are some distance from the main or upper portion encrusted 
with parasites. After removing portions of the encrusting case 
from the fascicle, he could not detect any structural evidence that 
Polython owed anything for food to the object which had 
gi- en it local support. It, however, ‘‘chums” with the sponge 
* _a purpose of its own. Prof. Lockwood thinks that it draws 
sastenance from the fishing process of its radiating tentacles. 
Both Polyps and sponge provide-for themselves. In his view 
the zodphyte is what we must call a compensal, and could not exist 
without that sort of support from Hyalonema which the oak 
affords the vine : and Hyalonema, too, is acompensal ; for how 
long would it endure without the support of Polython? The 
stem, without this support, would not be able to hold itself 
erect. Other varieties are supported by stems consisting of 
sheaves of short spicules, bound together by bony cement. These 
have and need no supporting Polythoa. He combated the view 
that Hyalonema was sunk in the mud up to the neck, arguing 
that the polyps surrounding the stem could not so live; that it 
could not use its tentacles to obtain food, and that the position of 
the egg-cases of the deep-sea shark, the oldest egg being attached, 
and the most recent at the bottom, sustained this view. Some 
account was then given of the material structure of the encoating 
Polython, The essayist spoke of the deep-sea sharks off Setubol, 
