Notes on Recent Literature. 
93 
NOTES ON RECENT LITERATURE. 
A NEW FERN-LIKE STEM, DESCRIBED BY 
COUNT SOLMS-LAUBACH. 
AST year Count Solms-Laubach 1 published a very interesting 
Jj account of a fossilised fragment of stem from Brazil. The 
fossil is evidently part of a Fern-like plant and appears to come 
from the same geological horizon as the Lepidodendra, Cordaiteas 
and Psaronieae that have been recorded by Derby from that part of 
Brazil. Count Solms gives to this new stem, from near Tiete, the 
name of Tietea singular is. 
The fossil consists of a fragment of a stem, at the periphery of 
which are the remains of two leaf-bases. The innermost part of 
the stem preserved—which may or may not represent the central 
region of the original stem—consists of a number of solenosteles 
scattered irregularly in an originally homogeneous ground-tissue. 
Usually these steles form closed rings, but the ring may be broken 
in one or more places, so that the place of a solenostele may he 
taken by a number of small strands more or less circular in transverse 
section ; in other cases the steles may bear irregular projections or 
branches. The xylem of these steles consists of the polygonal, 
scalariform tracheides so common in the Ferns; in each strand the 
xylem is broken up into nests of tracheides separated by rays or 
bands of parenchyma. There are also parenchymatous intrusions 
or splits. These intrusions are described as being widest at the 
periphery of the xylem, narrowing as they pass inwards and 
occasionally becoming branched ; they consist of rather small- 
celled parenchyma in connection with the surrounding phloem- 
parenchyma. Though the position of the protoxylem could not be 
certainly determined, owing to poor preservation, Count Solms 
thought that, if present, it was probably in contact with these 
intrusions. 
The leaf-traces are large; they originate by the division and 
branching of a number of peripheral steles of the stem. These 
leaf-trace-bundles at first form a transverse series, but, apparently 
somewhat irregular divisions soon give rise to three rows of small 
bundles, somewhat circular in transverse section, lying one outside 
the other. The two inner rows supplied the petiole; the outermost 
row, distinguished by the markedly larger diameters of its steles, 
passes out first and enters a sort of sheath (“Decke”). external to 
the trace. After entering the sheath the number of the bundles 
diminishes considerably; a little higher up the sheath itself forks 
into two divergent projections or lobes, and here the bundles 
undergo a further reduction in number, and the resulting bundles 
appear to be more freely branched or subject to greater fusion. It 
is from the bundles of these lobe-like projections that the vascular 
systems of the adventitious roots arise. 
1 “ Tietea singularis. Ein neuer fossiler Pteridineen stamm aus Brasilien.” 
Zeitschrift fur Botanik, Bd. 5, 1913, pp. 673-700, with Pis. VI and VII. 
