272 Journal of the Asiatic Society of Bengal. [N.S., XV, 
are a very poor safeguard. The stout woody stems and roots! 
are a much better guarantee for the survival of the species, ee 
those not only prevent the plants from being blown away 
broken in fragments but also preserve their vitality and dishie 
them to sprout again after their soft parts have been eaten. 
The thorns are ‘prob ably a protection rather against small 
desert rodents, phytophagous lizards (Uromastix) and possibly 
birds, than against camels Against the larger vertebrate ene- 
mies the very inconspicuous appearance of the vegetation of 
the stony desert is possibly an additional protection. At first 
nese! barren, paeahe as the lists given in this — 
in this respect, some plants having the leaves varying in colour 
from dull pink to dull green, while in others they are all. bright 
leaf-green. This variation is not correlated in any way with 
environment, for plants of the two colour-forms were found 
actually interdigitating in such a way as to appear to form a 
single flat clum irs 
species of Artem orange-brown infloreneanee and 
le glaucous sais leaves, and a Ruta which has yellowish 
leaves and flow The small white flowers of Heliotropium 
arbainense are also fairly conspicuous, and so also is the 
whole plant in Salsola joetida, and Halogeton? glomeratus, 
which are white and shining almost like a coral, and have star- 
like winged fruits varying in colour from scarlet to bihek 
colour between straw-colour, orange yellow and deep scarlet. 
Moreover, these fruits are produced in very great profusion, 
often almost concealing the rest of the plant Neverthe- 
less, in their natural surroundin ings they are not conspicuous, 
for the different shades harmonize in such a way that their 
essential brightness is hardly visible. In at least one species of 
the same family (Anabasis setifera) a stony desert form can be 
distinguished in which the whole plant is of an inconspicuous 
dull green colour, whereas another form, which grows among 
the bare clay hills (very little frequented by any kind of animal) 
that skirt the desert at certain places, the whole plant has a 
| Woody sane in the desert are often completely destroyed by Ter 
mites (Hodotermes ? vagans), but are probably not attacked by the insects 
tilldead. We have to thank Prof. Silvestri for examining specimens 
