Notes. 
1 68 
changes it to green, eventually destroying it. Light does not alter it. All parts of 
the plant except the flower can produce the pigment. 
Such a reducing agent as stannous chloride decolorizes an aqueous solution of 
the pigment. Micro-organisms can also readily bleach it, when oxygen is excluded. 
On allowing air to enter, the original colour at once returns. 
The whole phenomenon bears some resemblance to the way in which indigo 
arises in plant tissues. The chromogen of jacobinia is probably a glucoside. In the 
living cell this substance and its enzyme may be differently situated, perhaps one 
in the protoplasm and the other in the sap. On the destruction of the cell the 
two come in contact. The first result is the formation of a colourless body. Then 
this through the oxygen of the air, possibly assisted by an oxidase, is changed into 
the pigment. 
This behaviour of the Jacobinia is perhaps only a striking instance of a common 
feature of plant-juices, viz. their tendency to darken on exposure to the air. 
J. PARKIN. 
Cambridge. 
ON THE STRUCTURE AND AFFINITIES OF FOSSIL PLANTS FROM 
THE PALAEOZOIC ROCKS.— V. ON A NEW TYPE OF SPHENOPHYLLA- 
CEOUS CONE (SPHENOPHYLLUM FERTILE) FROM THE LOWER COAL- 
MEASURES. — (Abstract.) L— The class Sphenophyllales, of which the fossil described 
is a new representative, shows on the one hand clear affinities with the Equisetales, 
while on the other it approaches the Lycopods ; some botanists have endeavoured to 
trace a relation to the Ferns. The nearest allies among recent plants are probably 
the Psilotaceae, which some writers have even proposed to include in the Spheno- 
phyllales. 
The new strobilus appears to find its natural place in the type-genus Spheno - 
phyllum , as at present constituted, but it possesses peculiar features of considerable 
importance, which may probably ultimately justify generic separation. The specimen, 
of which a number of transverse and longitudinal sections have been prepared by 
Mr. Lomax, is from one of the calcareous nodules of the Lower Coal-Measures of 
Lancashire, and was found at Shore Littleborough, a locality rich in petrified remains, 
now being opened up by the enterprise of the owner, Mr. W. H. Sutcliffe. 
The close affinity of the strobilus with Sphenophyllum is shown by the anatomy 
of the axis, which has the solid triarch wood characteristic of that genus, and by the 
fact that the whorled sporophylls are divided into dorsal and ventral lobes, as in all 
other known fructifications of this class. But whereas, in all the forms hitherto 
described, the lower or dorsal lobes are sterile, forming a system of protective bracts, 
while the ventral lobes alone bear the sporangia ; in the new cone, dorsal and ventral 
lobes are alike fertile, and no sterile bracts are differentiated. On this ground the 
name Sphenophyllum fertile is proposed for the new species. 
Each lobe of the sporophyll divided palmately into several segments, the 
sporangiophores, each of which consisted of a slender pedicel, terminating in a large 
1 Read before the Royal Society, Dec. i, 1904. 
