ON THE STRUCTURE OF THE FRUIT OF CALAMITES. 351) 
from Phanerogamous plants, that the special alteration of each alterna- 
ting whorl for the protection of the sporangia indicates a higher structure 
than the conversion of all the leaves into fruit-bearing organs. And 
- "B 
this opinion is established by a comparison of the stems and foliage of 
the recent with those of the fossil plants. The Order Equisetacece, 
represented by the single genus Equisetum among recent plants, con- 
sists of herbaceous plants, with striated fistula?, branching and jointed 
stems, each joint terminating in a toothed sheath, which is the only 
foliage they possess. The stems are composed chiefly of cellular sub- 
stance, with a few regularly-disposed bundles of annular and spiral 
vessels. Catamites, on the other hand, were plants with true leaves, 
and with arborescent and evidently perennial stems, the vascular tissue 
of which was entirely scalariform. The annular and spiral vessels are 
the only characters in the recent plants that may be held to indicate a 
higher position for them as opposed to the scalariform vessels of the 
fossils, a vascular structure existing in Ferns which form the bulk of 
the vascular Cryptogams, to the exclusion of other vascular tissue ; 
yet this structure is not confined to them, but is found associated 
with other vascular tissue in plants of a much higher position, as in 
Gycadece, Euphorbiacece, etc. The stems of Catamites have been de- 
scribed as possessing medullary rays. I have never met with any 
indications of them in any stems I have examined. The radiating 
laminae of cells interposed between the wedges of vascular tissue are 
perpendicular and not horizontal structures, and differ entirely from 
medullary rays. It is more than probable that steins belonging to 
widely-different genera have been described under Odontites or some 
of its synonyms. While, then, the strobilus scarcely differs from that 
of Equisetum, and necessitates these fossils being placed in this Order, 
its structure, as well as the structure of the whole plants, clearly indi- 
cate that the paleozoic fossils were a more highly organized group oi 
plants than their representatives of the present day. 
Brongniart, in the paper already quoted, refers the family Asterophjl- 
liiem toGvnmosperms, including in it an arborescent stem (hhmoim- 
drou (Calami*, Cotta) ; three forms of foliage, Aster ophjlhtes , Sphe- 
nopkyllu. . and Aumdaria, with the fruits which he believes belong to 
the first of these forms, and have been described under the names 
Folkmannia, Becker a, Bornia, and Brucimamm; a somewhat doubtful 
Mm, with leaves, Ilippurites gigautea, figured by Lindley and Hutton, 
