Lycopodiaceous Cones from the Lower Coal Measures. 381 
it retains this width until it expands into the base of the lamina (Phot. 
1 and 4). 
The horizontal portion is composed of somewhat thick-walled cells 
which are slightly elongated radially. It is traversed throughout its entire 
length by the vascular bundle, which passes straight through it. The wood 
of this bundle arises from the wood of the main axis and ascends steeply 
through the phloem and inner cortex, as is shown by the number of traces 
met with in this region in transverse section. It passes quickly through the 
Text-FIG. i. Diagrammatic median longitudinal section of a cone of Mesostrobus Scottii. 
x 1 2 approx. The sporophylls should not be superposed, but there is evidence for all other characters 
shown. Black = vascular tissue ; White = middle cortex and parichnos ; Horizontal lines = sclerized 
areas ; Dotting = parenchyma. Lg = Ligule ; Tt = Transfusion tracheids at its base ; Sm = Sporan- 
gium ; Sp — Sporophyll. 
middle cortex and into the outer cortex, into which it is accompanied by 
only a very small strand of middle cortex as a parichnos. In its course 
through the outer cortex it is surrounded by a sheath of parenchyma which 
fills up the hole in the plate of sclerized tissue which supports the sporophyll. 
In the mid-region of the horizontal portion I have not been able to see any 
definite parichnos, but I believe it occurs further out, as will be shown later. 
The horizontal portion of the sporophyll at about 3 or 4 mm. from the 
axis broadens out tangentially and vertically to form a solid mass, which is 
the base of the lamina (Phot. 6 and 7) ; in this region the bundle takes 
