Slopes. — A Note on Wounded Catamites. 
279 
Diagram 3. Neighbouring sect. R. 102. x 2. Noinrolled 
wedges, groups of wood associated with primary bundles cut 
off by cambium, and inverted strands facing them in pith 
cavity. Cf. Fig. 1, PI. XXIII. 
as occurring commonly just at the point of exit of branches in normal 
Calamite stems (see Williamson 1 , Fig. 28, PL XXI, and Fig. 17, PI. XX), and 
is also a character of the callus wood of many plants, see Kiister, p. 1 77 2 . 
The exact shape of 
the wound is not to be ^ 
determined from the small 
number of sections avail- 
able, and may have ex- 
tended for some distance 
down the stem, where it 
may not have closed com- 
pletely; in those sections 
which we have, however, 
the wound was exter- 
nally closed up, and the 
wood formed outside it 
(as in Diagram 3) is 
entirely normal in ap- 
pearance. As the figures show, the total thickness of the normal secondary 
wood is greater on the injured than on the uninjured side. 
The formation of inverted 
strands of wood in the pith 
is to be looked upon simply 
as a result of the stimulus 
of the wound, and the phy- 
sical conditions and space 
opened out by the breaking of 
the vascular cylinder. It is 
hardly to be supposed that 
they are of phylogenetic im- 
portance, or in any way to be 
compared with the inverted 
strands in the Pteridosperms 
and Gymnosperms. They pro- 
bably find a close analogy 
among the fossils in the in- 
rolled secondary wood in a Lepi- 
dodendron described and figured 
by Williamson 3 , p. 293, and Fig. 20, PL XLIII, in which the dicho- 
tomizing cylinder did not close up to form two complete rings as is usual, 
1 W. C. Williamson, On the Organization of Fossil Plants, Pt. IX, Phil. Trans., 1878. 
2 E. Kiister, Pathologische Pflanzenanatomie, 1903. 
8 W. C. Williamson, On the Organization of the Fossil Plants of the Coal-Measures, III, Phil. 
Trans., 1872. 
Diagram 4. Trans, sect, of second specimen, x 2. 
Wound at a-, externally closed, but showing in pith 
inrolled strands of wood. 
