sland south of the equator,
and surrounded by vegetation of a totally different order, appeared to
be so inexplicable that the hypothesis of a separate and distinct origin
was advanced. A more satisfactory explanation has, however, been
furnished by Darwin, which is now generally accepted. Very briefly,
this is as follows. It is supposed that at the time of the glacial epoch
the depression of temperature was so great as to admit of the prevalence
in the tropics of forms of plants now peculiar to the temperate regions
of the north. As the heat increased, such plants retreated from the
tropics, for the most part northwards, but not exclusively. Following
the snow-line, they also climbed to the cool heights of the lofty
mountains of Central India and of Abyssinia, and even crossed the
equator. They now linger upon the summits of the Javan mountains, and
furnish by their presence an additional proof of the original union of
the western islands of the Archipelago with the continent of Asia.

During his stay at Buitenzorg, Mr. Wallace ascended the mountains
Pangerango and Gede. He describes this expedition as "by far the most
interesting incident" of his visit to Java, and gives a full account of
the various European plants which he found growing at different
altitudes. In particular he mentions the royal cowslip (_Primula
imperialis_), "which is said to be found nowhere else in the world but
on this solitary mountain summit," and the stem of which he found
sometimes growing to a height of over three feet. The list of families
of European plants growing upon Pangerango and Gede given by another
scientific traveller, Mr. Motley, includes, among others, such familiar
names as the violet, the buttercup, the primula, the lily of the valley,
the honeysuckle and the wood-sorrel. I have already mentioned the fact
that it is found possible to grow all European plants (but not fruits)
in the mountain garden which is established on the slopes of Gede, and
which forms part of the Government gardens.

Of the tropical fruits in general I am inclined to think that their
excellences have been very much over-estimated. There is nothing to
equal or approach a fine jargonelle pear, a peach, or hothouse grapes.
The orange, cocoanut, banana, and mango are so well known as to need no
special description. In addition to these, the commonest fruit are the
pomelo, the mangosteen, the duku, the rambutan, and the durian. The
pomelo is six or seven in