280 Scientific Intelligence. 
that natural division, so long as no known stems or leaves can be refer- 
red there. Thus, the conclusion to which all researches up to the 
present time seem to lead is, that the terrestrial vegetation of the coal- 
epoch was limited to two great divisions of the vegetable kingdom, viz. 
the Acrogenous or Vascular Cryptogams, and the Gymnospermous 
Dicotyledons. A. Gr. 
3. Structure of the Trunk of Crean circinalis, (Ann. Sci. Nat., Jan. 
1846.)—From the examination of some old trunks of Cycas received 
from Java, Prof. Miguel draws the following conclusions.—1. The stem 
of Cycas is composed of two sorts of elementary organs, viz. parenchyma- 
tous cells and dotted vessels, agreeing in this respect with the structure of 
Conifers. _ 2. In the distribution of these elementary organs, it differs 
greatly from that of Coniferz : the wood is disposed in irregular concen- 
tric layers, confluent at certain points, unequal, sits no relation with 
the buds. , Separated by broad layers of eellular p pa .. 3) Inthe 
development of the tissues there are several pecolitvities which are not 
found in Conifer ; for instance; in mes aeeaes of the trunk in —_ 
from the summit only, in the p tous cells, i 
the ligneous parts being traversed by cortical parenchyma, &e, 4. In 
this acrogenous growth and by the clefts in the woody layers, there is a 
distant resemblance with the trunk of Ferns; but the continuous pe- 
ripheric growth is a complete distinction. 5: The structure of the 
trunk of Cycas, in all its peculiarities, more nearly resembles certain 
_ vegetables of a former epoch, than of the present. The author then 
compares the trunk of Cycas with that of Zamia and Eucephalastos, 
which have a single woody cylinder, with or without medullary rays. — 
hed an os. Qe Aah eee A: Gai 
VI. AsTRONOMY. 
A. Fifth Comet, of 1846.—The comet discovered Mey 19, 1846, by 
Mr. George P. Bond, of Cambridge, Mass., and the elements of which 
were published at p. 138, had been previously detected (on the 2d of that 
month) by the sharp-sighted astronomers of the observatory at Rome. 
Mr. B. was, however, the discoverer, so far as America is concerned, 
both of this comet and also of that whose elements are given at p. 44 
of vol. i, 2d Ser. ; and is entitled to none the less credit, because an- 
peipeted by one of the large corps of European observers. 
_ 2. Antares, a triple star.—Prof. Mitchel of the Cincinnati observa- 
ew found in June, 1845, that Antares is accompanied by a minute 
Star distant only 1-7’. In a communication dated July 30, 1846, in the 
Union, Lieut. Lieut. M: F. Maury, of the Washington observatory, announces 
the « is 0" ron jou: wena sheseraint: Abinyatar cans a seaeae companion, 
if i ———— 
