Notes. 
1 75 
Sphenophyllum Dawsoni, or S. cuneifolium , according to M. Zeiller’s 
interpretation \ 
4. The differentiation of the sporophyll into sterile segments 
(bracts) and fertile segments (sporangiophores). The comparison 
with Sphenophyllum is much strengthened if, as I believe to be the 
case, the segments of the inferior lobe in Cheirostrohus are sterile, 
and those of the superior lobe fertile. 
5. The repeated subdivision of the leaf-trace vascular bundles, in 
passing through the cortex of the axis 1 2 , as in Sphenophyllum 
Stephanense. 
6. The attachment of the sporangia to a laminar expansion at 
the distal end of the sporangiophore. As regards this point, com- 
parison should be made with the Bowmanites Romeri of Count 
Solms-Laubach (loc. cit.). 
7. The structure of the sporangial wall. 
I think that the sum of these characters, to which others might be 
added, justifies the suggestion that Cheirostrohus may be provisionally 
placed in the same phylum , or main division, of Pteridophyta with 
Sphenophyllum , though indications of possible affinities in other direc- 
tions are not wanting, and will be discussed on another occasion. 
Cheirostrohus , even more than Sphenophyllum itself, appears to 
combine Calamarian with Lycopodiaceous characters, and might 
reasonably be regarded as a highly specialized representative of an 
ancient group of plants lying at the common base of these two series. 
It appears likely that in Cheirostrohus one of those additional forms 
of Palaeozoic Cryptogams, allowing of comparison with Spheno- 
phyllum, , has actually been brought to light, the discovery of which 
Dr. Williamson . and I ventured to anticipate at the close of our first 
joint memoir 3 . 
NOTE ON THE DISCOVERY OF MYCORHIZA.— In the 
Botanische Zeitung for 1886, Wahrlich gives (p. 481) the early 
bibliographical history of Mycorhiza. He says, ‘ Schleiden war der 
1 Etude sur la constitution de l’appareil fructificatif des Sphenophyllum. Mem. 
de la Soc. Geol. de France, Paleontologie, Mem. 11, 1893, p. 37. 
2 Cf. Renault, Cours de Botanique fossile, Vol. ii, Plate XIV, Fig. 2 ; Plate XV, 
Fig- 3 > Vol. iv, p. 15. 
3 Williamson and Scott, Further Observations on the Organization of the 
Fossil Plants of the Coal-measures, Part I, Phil. Trans., 1894 B, p. 946. 
