Scott. — On two new instances of Spinous Roots. 331 
practically identical in structure with the normal absorptive 
roots. In both alike, the mature root consists chiefly of the 
vascular cylinder, on which the dead cortex hangs loosely ; 
in both the endodermis is greatly thickened, and the con- 
junctive tissues of the stele much lignified. The only 
difference of importance is that the more internal vessels 
of the spinous roots are smaller than those of the normal 
organs. 
The spines themselves, which are often branched, are mani- 
festly rootlets, having essentially the same structure as the 
roots which bear them, except that in the spines the vessels 
are still further reduced. 
Numerous small corms, varying in size from that of 
mustard-seed to that of a hazel-nut, bud out from the basal 
part of the main stem, among the spinous roots, which 
perhaps serve more especially for their protection. The 
corms easily become detached, and afford an abundant means 
of propagation. Young plants are now being raised at Kew 
from some of these corms, so it may be hoped that the whole 
development of the plant, especially that of its remarkable 
root-system, may be followed as time goes on. 
The fact that earth is present among the roots, in all parts 
of the cluster, no doubt indicates that the whole mass was 
developed in the soil. It would be interesting to ascertain 
whether in nature it ever becomes loosened from its attach- 
ment to the ground, and carried away by wind, like a ‘ Rose 
of Jericho. 5 It is possible that the corms, which separate so 
readily from the stem, may be distributed in this way. 
I am indebted to the Staff of the Royal Gardens, Kew, 
and especially to Mr. W. Watson, Assistant Curator, for much 
information concerning these plants. The present preliminary 
communication is only intended to record the main facts as 
to the curious and exceptional forms of root illustrated in the 
photographic plates. 
When opportunity arises, I hope to enter on a full investi- 
gation of the development and histology of the organs in 
question. 
