VII.] VEGETATION OF INDIA. 139
important arm in former times, for in this part the course of the
Indus has been subject to many changes. At the present day the
principal bifurcation of the stream is at Tatta, fifty miles lower
down than Hyderabad, but Tatta is too near the sea to correspond
to the position which is given by the historians of the expedition.
Alexander himself descended to the Indian Ocean, and enjoyed
the satisfaction of sailing on its waters. On this occasion we are
told that his soldiers were affected with great terror at the un-
wonted sight of the tide1. The terms which Arrian
here uses, however, leave no doubt that what is indus!° *
meant is not the ordinary ebb and flow of the tide,
but the bore or inrush of the flood tide, which is a remarkable
phenomenon at the mouth of the Indus, and other great
Indian rivers. This at times rises to the height of many feet,
and produces a violent noise, when it meets the current of
the descending stream. Their curiosity also was „ „ _
. , , , , . i -r ,. Indian Trees.
excited by the unwonted vegetation of India, of
which the historians have left descriptions—especially the honey-
bearing tree (Borassus fldbelliformis\ the banyan-tree (Ficus indica)y
with its strange mode of growth, and the cotton-tree (Bombax
malabaricum) with its seed-vessels bearing tree-wool3. The follow-
ing is the account which is given of the banyan-tree:
" Onesicritus tells of certain large trees, the branches of which,
when they have grown to the height of twelve cubits, subsequently
grow downward, as if they were bent down, until they touch the
earth; after which they spread underground and take root like
layers, and then spring up and grow into a stem: after that again,
according as they grow, they are bent down, and form first one
and then another layer, and so on continuously, so that from one
tree proceeds a long sunshade, resembling a tent supported by
many poles, ige^speaks also of trees which are of such a size
that fiy^men_ca.n with difficulty clasp their trunks."
"Alexander was now making preparations for his return journey.
He had already despatched a large part of his army Retani
under the command of Craterus from the point March of
where the Indus receives the combined waters of through*
the Punjab rivers; this detachment was to mardh
1 Arrian, 6.19. 1,2. * Strabo, 15. i. 21.