306 Recent Literature. [ZOE 
carboniferous formation, that they possess reservoirs of tannin or 
various mucilaginous matters, besides resiniferous ducts in great 
abundance. This is the case for instance in Sigillaria, the 
bark of which shows numerous secreting ducts; in the petioles of 
Myelopteris which are almost perforated by gum-ducts; in the 
leaves and branches of the Dolorophylleze, where each mestome- 
bundle is accompanied by numerous ducts; and in the outer- 
most layers of the bark in Colpoxylon, Medullosa and 
Cycadoxylon which show the presence of a very large number 
of gum-reservoirs. Such examples might easily be multiplied 
A very interesting addition to this flora of the permo-carboniferous 
formation is the new genus Retinodendron, which the author 
describes in the present paper. 
The material, upon which the genus has been established, 
was collected near Autun, in France, by Mr. Rigollot. It con- 
sisted of a stem, of which only the inner part was preserved; the 
bark was, unfortunately, wanting. The author succeeded, how- 
ever, in identifying the family to which this stem belonged, and 
he has referred it to the Gymnospermze on account of the struc- 
ture of the hadrome. 
The leptome showed the singular fact, that certain parts were 
composed of several concentrical zones of gum-ducts and sclerotic 
cells in regular alternation with each other. The content of 
these gum or probably resin ducts was a brown and somewhat 
granular substance. The ducts themselves were surrounded 
rounded by a sheath of thin-walled cells, around which another 
sheath was formed of similar cells, the walls of which showed 
some kind of irregular perforation. ‘This first zone of gum-ducts 
included about fifteen concentrical rows, but outside this was a 
second zone, consisting of twenty-four rows of similar ducts; 
thereupon followed a circle of sclerotic cells, after which again a 
third zone of more than fifty concentrical layers of the same 
gum-ducts, as described above. 
This very regular arrangement of the ducts and sclerotic cells 
reminds one of the Poroxylez; but in the latter it is the sieve- 
tubes and parenchymatic cells, which show this regular 
arrangement, 
