209 

NATURE 
| Fan. 5, 1871 

an electric discharge would first illuminate the atmosphere of the 
comet, or even carry some of the solid material off in a state of 
vapour, and then pass off to the surrounding medium. Thus 
while the spectrum from the head would be that of cometary 
matter, the tail would be due to the incandescent ether. 
I would here suggest that gas, when rendered incandescent by 
electricity, may reflect light—it will certainly cast a shadow 
from the electric light—and if this be the case, part of the light 
from comets’ tails may after all be reflected sunlight. 
At any rate, it is certain that the appearance of streamers, the 
rapidity of change and emission, the perfect transparency and 
the wave-like fluctuations which belong to these phenomena, 
are all exhibited by the electric brush ; in fact, the electric brush 
will explain all these appearances which have defied all attempts 
at explanation on a material hypothesis. I have only to add 
that the main assumption involved in the electric theory is that 
space is occupied by matter having similar electrical properties 
to those of gas; and I would ask, is it not more rational to 
make such an assumption than it is to attribute unknown and 
inconceivable properties to cometary matter? Theories, even if 
founded only on rational speculation, often, I believe, prove 
very useful, inasmuch as they afford observers a definite pur- 
pose in their observations—something to look for, something to 
establish or to refute ; and I publish these speculations of mine 
at this particular moment in the hope that they may perchance 
serve such a purpose. 

PHILADELPHIA 
American Philosophical Society, October 7.—Dr. Binton 
made some observations on a Mazahc theological work and 
grammar, indicating probable resemblances between the language 
of that nation and that of the Aztecs. He also described a 
grammar of the Moska nation of New Granada, prepared by 
Father Lugo.—J. A. Macneil described the ruins and other re- 
mains of the ancient nations, which he had discovered during 
several expeditions in Nicaragua, Costa Rica, Chiriqui, and 
Chiapas. He made especial reference to an extensive series of 
ruins he had discovered near the boundaries of Chiriqui and 
Costa Rica. One of the buildings was 600 feet in length, and 
25 to 30 feet elevation. Among other sculptures he observed 
a well-executed stone alligator of large size. — Prof. Cope 
exhibited the remains of a new cretaceous tortoise, of 
the genus Adocus Cope, to be called A. syntheticus. He 
explained that he had been able to establish more fully 
the characters of the genus Adocus ; that it was found to possess 
an intergular shield as in the Pleurodira, but had not the sutural 
union of the inferior pelvic elements with the p!astron of that 
type. He said that these characters had been heretofore known 
as correlatives from the cretaceous period to the present day, and 
that this genus presented us with the first exception to the rule. 
The genus was therefore regarded as a generalised type, and to 
be elevated to the rank of a family. Prof. Cope exhibited a 
metatarsus of Zuclaps aguilunguis, the first known, and said it 
proved the distinctness of those elements from each other in that 
type, and their slenderness, taken collectively. The specimen 
was an external one, without trace of a rudimental one outside of 
it ; that its measurement, 16 inches, was indicative of a length 
of 18 inches to the median metatarsus, a length he had already 
assigned to it, on theoretical grounds. Prof. Cope read a paper 
entitled, ‘‘ Contribution to the Ichthyology of the lesser Antilles.” 
Two new genera were described in it, viz., A/ewtheractis and 
Cryptotomus. 
Academy of Natural Sciences, November 8. — Prof. 
Leidy characterised three species of extinct turtles, obtained 
by Prof. Hayden’s party from the tertiary deposits of Wyoming. 
Two were named Lmys Haydeni and £. Feanest. The third, 
partaking of characters of the genera Chelydva and Derma- 
temys, was named BLaena arenosa. A lacertian, as large as 
the largest of our living Iguanas, was characterised from the 
greater part of the bones of a skeleton imbedded in a rock 
of tertiary age, from Wyoming. ‘The vertebra have the cha- 
racteristic ball and socket-joint to the bodies, but they are 
devoid of the zygosphene and zygantrum. The teeth are com- 
pressed conical, slightly curved, sharp-pointed, and trenchant. 
The remains were referred to a species with the name of Saviwa 
ensidens, The names Baena and Saniwa, according to Prof. 
Hayden, are those given to the turtle and lizard by one of the 
aboriginal tribes of the Upper Missouri. 
VIENNA 
I. R. Geological Institute, December 6.—Dr. Laube pre- 
sented a memoir on ‘‘the Echinidze of the Upper Tertiary De- 

posits in the Austro-Hungarian Empire,” which will be printed 
in the fifth volume of the Memoirs of the Institute. The total 
number of distinct species is 37, six of which belong to the lower, 
and 31 to the upper part of the Mediterranean formation.—M. 
F. Foetterle ‘‘on the Sarmatic formation in the Bukowina and 
Northern Moldavia.” It occupies an enormous space in both 
countries, and is easily divided in two members, an upper formed of 
yellow sandand sandstone, and a lower which consists of blue clay. 
Both contain fossils in abundance. The clay is everywhere per- 
meated with very thin veins and layers of fine sand, which give 
free access to water, and thus cause the greatest difficulties for the 
railroad between Czernowitz and Jassy, which for long tracts 
passes over the clay, and is damaged by very long continued falls 
of rain.—M. Th. Fuchs reported onthe Fauna of the Congeria- 
beds of Tihany and Kup in Hungary.—M. Ch. v. Hauer com- 
municated the analysis of fire-proof clay of Fohnsdorf (Styria) 
which forms there a layer 9 feet thick in the browncoal basin. 
It consists of a hydrosilicate of alumina and magnesia, and 
belongs to the so-called soap-stones.—M, E. Tietze gave notice 
of the discovery of fossiliferous beds belonging to the brown Jura 
at Boletin, in Servia, and of neocomian and turonian beds in 
north-eastern Servia.—-M. M. Neumayr presented a memoir 
on the jurassic flint-limestones of the Carpathians.—M. D. Stur 
exhibited a magnificent collection of eocene fossils from the en- 
virons of Vicenza, which had been purchased for the Museum of 
the Institute. 


DIARY 
FRIDAY, January 6. 
GeotoaistTs’ AssoctaTION, at 8. 
SATURDAY, January 7. 
Royat Ins riTuTION, at 3,—Burning and Unburning: Prof, Odling (juvenile 
lectures). 
SUNDAY, January 8 
Sunpay Lecture Society, at 3.30.—Malta and the Maltese, with a visit to 
St. Paul's Bay : Dr. Carpenter. 
MONDAY, January 9. 
Roya GEOGRAPHICAL SOCIETY, at 8,30. 
TUESDAY, January to. 
Puotocrapnic Society, at 8. 
ETHNOLOGICAL Society, at 8.—On the Prehistoric Remains in Brittany : 
Lieut. S. P. Oliver, R A—Exhibition of Stone Implements from Queen 
Charlotte’s Isand: Dr. Hocker, C.B.—On a Cairn near Cefn, St. Asaph: 
Rev. D. R. Thomas, M.A., and Mr. T. McK. Hughes, M.A. : 
WEDNESDAY, January 1t. 
Gro.ocicat Society, at 8.—On the older Metamorphic Rocks and Granite 
of Ranffshire: Mr. T. F. Jamieson, F G.S.—On the Connection of Vol- 
canic action with Changes of Level: Mr. J. J. Murphy, F.G.S.—On the 
Geology of the neighbourhood of Malaga: Don M. de Orueba. 
Royat Microscoricat Society, at 8—On the Anstomy of Ascaris lum- 
bricordes: Mr. B. LT. Lowne, M.R.C S.—On the use of Collo.d Silica in 
preparing Crystals for the Polariscope: Mr. H. J. Slack. 
THURSDAY, Janvany 12. 
Royat, at 8.30. 
SOcIETY OF ANTIQUARIES, at 8.30. 
Lonpon MATHEMATICAL Society, at 8.—On Systems of Tangents to Plane 


Cubic and Quartic Curves: Mr. J. '. Walker.—On the Order and Singu- 
lar ties of the Parallel of an Algebraical Curve: Mr. S. Roberts. 
CONTENTS Pace 
PROGRESS, OF SCIENCE IN I87O 5 «© «= « |», =| 5, pelle neue 
Tue INTELLIGENCE AND PERFECTIBILITY OF ANIMALS. By A. R 
WALLACE, BiZiSH SS eee ey an eee 
Our Book SHEUFi%s.%<\- 4 Gr 6: 0) leh << Wa ce Selle Ve. tone ne RE 
LETTERS TO THE Eprror :-— 
The Eclipse Expedition —L. CumMING. . . « . © « « « « 184 
The Eclipse. (Wat filustvation:.) . 2. +... 3 «6 = «205 
Eozéon Canadense.—Dr. W. B. CarPenTeR, F.R.S.. . . . - 185 
Mimicry versus Hybridisation —A. Murray, F.L.S. «. « + 186 
Measurement of Mass .« Pr A, 3: 
PuoToGRaPuic PROCESSES O¢ THE PRESENT Day .. . . . . « 189 
PuysioLocicALt LABORATORIES IN GREAT Brirain. By Dr. J. Bur- 
DON SANDERSON, F.R.S. cote, (gig Se asf.) ©. Se 
New ZEALAND ANIMALS IN THE ZOOLOGICAL SociEtY’s GARDENS. By 
Dr. P. L. Scrarer, F.R.S. (With Iilustrations.) . . .« « « + 190 
INGTHS Wu wes, Romanians Bo ce cigar MCI DC ce cr cece = EY 
Tus ECuipst EXPEDITION. civ Mapmnteeetee ke” Core” ohh le. ote aCe 
SocigTIES AND ACADEMIES. « 2 5 « «© «© © © «© «© «© «© © © « 197 
DOTARY 1) isuilen is) iene ak’ Mace us:. fo 6 10 “ive suinn en oe eS 


