324 
HICK AND CASIf: AFFINITIES OF LEPIUODENDRON. 
phellem or cork, though a little is said to occur in Lepidodendron 
selnginoidea/'' 
III. The Leaves. 
Speaking generall)^ of the whole group oi Lepidodendrea', Schenkf 
states that the leaves are in part like tliose of the Lycopod'iw and 
Coniferw, linear, pointed, and sometimes of considerable length, as in 
L. longifoUum, Brong. ; or shorter, as in L. brevifolium, Ettingsli. ; 
or again lanceolate, as in L. Haidingeri, Ettingsh. ; or finally, short 
and linear, with tips curved inw^ards as in L. selaginoides, Strnbg. 
With reference to the leaves of L. RhodumupAise, Solms-Laubach 
saysj that they stand off from the stem at right angles, and then 
curve upwards like a hook. He adds that the transverse section of 
the base is rhomboidal, while that of the upper part is crescentic, 
and that there is a single median vascular bundle. Under which 
type of bundle this is to be placed has not been definitely determined, 
some regarding it as collateral and others as concentric, || 
The leaves of Lepidodendron were deciduous, and have left behind 
the well-known scars and cushions by which the older palyeonto- 
logists distinguished the various forms from one another. After the 
fall of the leaf the cushions appear to have grown wdth the growth of 
the stem. The leaves being small and closely crowded round the 
stem on all sides the pbyllotaxis is somewhat complicated, though 
the parastichies are, as a rule, well marked. 
IV. The Fruits. 
The fruits of Lepidodendron, known as Lepidostrobi, are cone-like 
shoot-tips, densely clothed with more or less modified foliar leaves or 
sporophylls, which bear sporangia containing spores. The outward 
appearance has some resemblance to the cones of Lycopodium and 
Selaginella, though these are extremely diminutive compared with 
Lepidostrobi. 
The size of the fruits varies within wide limits as do the indi- 
vidual sporophylls and sporangia, both in size and shape. 
♦ EinleituDg in di^ Palaophytologie, Von II. Grafen zu Sojms-Laubach, p. 227. 
t Dk foesilen Pflanzenreste. Von Dr. A. Schenk p. 60. 
J Einleitung in di^ Palaophytologie, Von H. Grafen zu Solms-Laubach, S. 222. 
II Solms-Laubach. Loc. cit., p. ^25. 
