334 
NATURE 
te! 
[F2b. 27, 1873 
limestone is formed from the sea-water by the agency of animals, 
but no creature is known which secretes carbonate of magnesia 
from the sea waters to make its skeleton, and therefore we may 
conclude that it was precipitated from chemical solutions ; and 
this could not take place in the open sea, but must have occurred, 
as in thecase of rock-salt in confined inland waters. It is 
probable that by extensive changes in physical geography, large 
areas of the ocean were shut off, and in the lakes thus formed, 
the Permian rocks were deposited, the magnesian limestone 
being formed by the mixture of the carbonate of magnesia, precipi- 
tated by means of evaporation with limestone built up by 
organic agency. Crystals of gypsum too occur in these rocks, 
and pseudomorphous crystals of rock-salt pointing to evapora- 
tion, and consequently conc=ntration of these salts in the waters 
of confined areas. A thin pellicle of peroxide of iron surrounds 
the grains in the sandstone and marl, which gives the red colour 
to the rocks, and which peroxide was formed by the reduction 
of the carbonate of iron, carried into the lakes by the rivers, by 
means of the oxygen of the air. The lecturer had no hesitation 
in saying that in all those formations which we know to be 
truly marine, the rocks are never red. So that from the paucity 
or absence of shells, from the remains of terrestrial or amphibious 
reptiles, and their foot-prints, from the occasional presence of 
true land plants (of the same genera, but not the same species, 
as in the carboniferous rocks), from the chemical composition 
of the rocks, from the presence of peroxide of iron, and from 
the presence of chemical precepitates, we are justified in con- 
cluding that the Permian rocks were deposited in great salt lakes, 
though perhaps not salt ia every case. And a refl-x of the 
conditions under which they were deposited may be seen in 
the state of the Caspian Sea (with a marine fauna like the 
North Sea, though the species are few and dwarfed), and of the 
salt lakes of Asia. 
SCIENTIFIC SERIALS 
Tue Lens for November 1872, contains the following com- 
munications: ‘‘ The preparation of Diatomacez,” Christopher 
Johnstone, M.D.: a succinct account of the most usual and 
approved methods of cleaning Diatomaceous deposits. A short 
reply of Dr. J. J. Woodward to Dr. Lionel S. Beale; and a 
memorandum by Chas. Stodder, entitled ‘‘ Draw-tubes v, Deep- 
eye-pieces.” A continuation by Dr. J. N. Danforth of his com- 
munication on “the cell,” treats of the theories of cell develop- 
ment. H. H. Babcock’s ‘‘ Flora of Chicago and its vicinity,” 
Part IV. completes, we presume, the phanerogamic plants of 
Part III. ; ‘‘ Microscopical Memoranda for the use of Practitioners 
of Medicine,” by Dr. J. J. Woodward, relates the results of the 
author’s experience on ‘“‘the Imbibition of the Tissues with 
Chloride of Gold and Osmic Acid.” Prof. H. L. Smith gives 
a brief notice of the Bailey Collection of Diatomacez in the 
Museum of the Boston Society of Natural History. Dr. j. J. 
Woodward also advocates the employment of Frussudia Saxonica 
as a test of high-power definition in preference to Amphipleura 
pellucida, S.A. Briggs gives an enumeration of some of the 
Diatomacee of Upper Lake Huron and the Sault. The usual 
brief notes, with title-page and index, complete this number and 
the first volume of this American Quarterly Journal of Microscopy. 
La Belgique Horticole, gives a short life of Redonte, the cele- 
brated French painter of flowers, A description of a new tea 
rose, the “Pearl of Lyons,” contains a short history of these 
plants, from which we learn that they w-re introduced into Eu- 
rope in 1793 by an Englishman, Mr. Parsons, and reintroduced 
early in this century by others, Sir A. Hume being one of them. 
M. E. Morren describes, in a very clear and concise manner, the 
physiology of the nutrition of plants. 
THE Revue Bibliographique Universelle contains short reviews 
of several botanical works, including that by Grisebach and En- 
gelman, on the geographical distribution of plants, in which the 
world is divided into twenty-four botanical regions, several of 
these being, according to the reviewer, unnecessary. Referring 
to a work by M. Hamilton on the Botany of the Bible, the fol- 
lowing occurs :—‘‘ Il a joint 4 chacun de ses articles une photo- 
graphie prise sur nature, mais malheureusement dans Jes environs 
de Nice, et non point en Terre Sainte.” Prof. Balfour's Intro- 
duction to the Study of Palzontological Botany is considered too 
deficient in detail and from the fewness of the references to other 
authors, the incompleteness of the Edinburgh libraries is pre- 
sumed, 
SOCIETIES AND ACADEMIES 
LONDON 
London Mathematical Society, Feb 13.—Dr. Hirst, presi- 
dent, in the chair. The following papers were read :—Prof. 
H. G. Smith, on the higher singularities of plane curves, and 
on systems cf linear consequences.—Mr. J. Macleod, on the 
application of the hodograph to the solution of problems on 
projectiles. ‘ 
Geologists’ Association, February 1.—Henry Woodward, 
F.GS., president, in the chair.—‘*On the Diprionidz of the 
Moffat Shale,” by Charles Lapworth, F.G.S. After reviewing 
the history of investigation among the biserial Grapfolites, and 
the antagonistic opinions regarding their internal structure held 
by different palzeontologists, the author stated that a careful de- 
composition and examination of specimen of Chinacograptus trom 
the Moffat Shale, preserved in a state of relief, had forced him to 
the conclusion that the view of the duplicate nature of the poly- 
pary in this genus advocated by Professor Nicholson is substan- 
tially correct. The internal characters are identical with those 
in Diplograptus. The diprionidian polypary is in reality com- 
posed of two complete monoprionidian polyparies (each with its 
own ceenosarc, virgula, and distinct hydrotheze), placed back to 
back and coalescing along their flattened dorsal walls. There is 
certain evidence that this type of structure obtains among all, or 
nearly all, of the Moffat Chinacszrapti. Nevertheless, he was: 
not prepared to deny the accuracy of Professor Hall’s inter- 
pretation of the internal characters of his China(?)typicalis. As 
long as a single doubt remained upon this point, it was argued 
that it would be unsate to exclude Refiolites and its allies from the 
Dipliotide, which might meanwhile be considered as embracing 
three sub-families, D:plograplide, Retiolitide, and a third and in-' 
termediate sub-family, of which C.(?) ¢yficalis is the only known 
example. The sub-family Diplograptide will include all those 
species at present referred to Diplograptus and Chinacograptus, 
Now that the type of structure in these two genera is proved to 
be identical, a new system of classification is necessary. The 
only remaining characters which can in all cases be empioyed for 
the purpose o! separation at our command are the form of the - 
polypary and the shape and arrangement of the hydrotheca. It: 
was shown that the different species of the Dzplograptide 
naturally arrange themselves into five groups, clearly individual- 
ised by striking distinctions in these characters. Each of these 
groups, it was contended, was of sufficient importance to be con- 
sidered as forming a distinct and separate genus. In this way the 
genera Climacograptus (Hall) and Cephalograpius (Hopk.) would 
rumain untouched, and the author suggested that the generic term 
Diplograptus (M‘Coy) should be restricted in future to those — 
species of which Dif. folium (His.) is the type, and he proposed 
two new genera, viz., Orthograptus, to include those species re-~ 
sembling Dip guadrimucronatus (Hall) and Glyptograptus for 
those formed after the pattern of D. ¢amariosens (Nich.). The* 
second portion of the paper was devoted to a revision of the 
genera and species of Diplograptidz found in the Moffat Shales, 
and the following new species were described :—Orthograptus 
aculeatus, O. Carruthersi, O. fasilicus, O. Pageanus, O, explana 
tus, O. compactus ; Glyptograptus gregarius, G, per excavatus, 
G. modestus ; Chinacograptus styloidens, C. tubulzferus, C. Lon- 
gicaudatus, C. Wilsont, C. antiquus, C. brevicornis, C. mira- 
bilis. 
- Zoological Society, Feb. 18.—John Gould, F.R.S., V.P., 
in the chair.—The Secretary read a report on the additions that 
had b-en made to the Society’s collection during the month of 
January, 1873. Amongst these were specially mentioned a pair 
of Fruit-Bats from Formosa, presented by the Rev. Mr. Ritchie 
of Takoo, and a tapir from Paraguay, which presented some 
points of distinction from the ordinary form of the American 
tapir.—Prof. Newton, F.R.S., V.P., exhibited a print by Adrian 
Collaert (circa, 1580) containing the figure of a bird, cepied in 
Leguat’s ‘‘ Voyages ” (1708), and mentioned by the latter under 
the name of the ‘‘ Géant.”—Extracts were read from a letter 
received from Dr. John Kirk, H. B. M. Consul at Zanzibar, 
respecting a female koodoo, and other antelopes, of which he 
had obtained specimens for the Society.—Mr. Garrod gave a 
notice of the death of a kangaroo in the Society’s gardens, 
which had been caused by strangulation of the small intestine, 
| produced by the folding of the elongate caecum round a loop of 
the small intestine. —A communication was read from Prof. G. 
J. Allman, F.R.S., containing a report on the Aydroida col- 
