At first sight, therefore, the existence of flowers such as the violet, the buttercup, and the honeysuckle in an island 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 Gedé. 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 Gedé 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 Gedé, 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 inches in diameter, with a smooth green exterior, not unlike that of a water-melon; the fruit is pink in colour, and easily breaks up into sections. It tastes like a very dry and rather acid orange, and the peel makes an excellent bitter in sherry. The rambutan resembles a horse-chestnut in size and appearance, except that its shaggy exterior is red instead of green. The duku and mangosteen, on the other hand, are smooth and green, and in other respects resemble a walnut. All three, rambutan, duku, and mangosteen, provide a gelatinous substance with a delicate acid flavour. The durian is as large as a cocoa-nut, and its exterior is armed with spikes; the fruit is soft and pulpy, tasting like a custard in flavour, but it has a horrible smell, and possesses strong laxative qualities. Mr. Wallace devotes several pages to a description of its various qualities, remarking that "to eat durians is a new sensation, worth a voyage to the East to experience." Credat Judæus non ego. There is also a species of green orange, with a very thin skin and fine acid flavour, to be obtained in Java.
A general view of the products of the island has already been given in Junghuhn's table in [Chapter II.], and some of the more important have been subsequently described at length. Any account of the plants of Java would, however, be incomplete without a narrative of the introduction of cinchona into the East Indies.
This plant, from the bark of which quinine is obtained, is a native of Peru, and for a long time the Peruvian Government jealously maintained exclusive possession of it. Forty years ago, the Dutch Colonial Government despatched Haskarl, one of the officials of the Buitenzorg gardens, to Peru for the purpose of procuring cinchona seed. He succeeded in obtaining some seed of a very inferior quality, and the plantations produced from it were practically useless. In 1866, however, both the British and Dutch Indian Governments purchased small quantities of seed from Mr. Charles Ledger. From this seed the very valuable plantations of Java and Ceylon have been propagated. I have already described the method of cultivating Cinchona Ledgeriana adopted by the planters, and how advantage is taken of the extreme liability of the cinchona plant to hybridization. The manner in which the seed was secured forms an interesting episode in the history of scientific botany. The story is told by Mr. Ledger in a letter to his brother published in the Field of Feb. 5, 1881, in which it will be seen that these seeds were obtained at the cost of the life of Manuel, the naturalist's faithful Indian servant.
"While engaged in my alpaca enterprise of 1856, a Bolivian Indian, Manuel Tucra Mamami, formerly and afterwards a cinchona bark-cutter, was accompanying me with two of his sons. He accompanied me in almost all my frequent journeys into the interior, and was very useful in examining the large quantities of cinchona bark and alpaca wool I was constantly purchasing. He and his sons were very much attached to me, [201]and I placed every confidence in them. Sitting round our camp-fire one evening, as was our custom after dinner, conversing on all sorts of topics, I mentioned what I had read as to Mr. Clement R. Markham's mission in search of cinchona seeds. Now, Manuel had been with me in three of my journeys into the cinchona districts of the Yungas of Bolivia, where I had to go looking after laggard contractors for delivery of bark. It was while conversing on the subject of Mr. Markham's journey, and wondering which route he would take, etc., that Manuel greatly surprised me by saying, 'The gentleman will not leave the Yungas in good health if he really obtains the rogo plants and seeds.' Manuel was always very taciturn and reserved. I said nothing at the time, there being some thirty more of my Indians sitting round the large fire. The next day he reluctantly told me how every stranger on entering the Yungas was closely watched unobserved by himself; how several seed-collectors had their seed changed; how their germinating power was destroyed by their own guides, [202]servants, etc. He also showed me how all the Indians most implicitly believe, if, by plants or seeds from the Yungas, the cinchonas are successfully propagated in other countries, all their own trees will perish. Such, I assure you, is their superstition. Although there are no laws prohibiting the cinchona seed or plants being taken out of the country, I have seen private instructions from the prefect in La Paz ordering strictest vigilance to prevent any person taking seed or plants out of the country. More than half a dozen times I have had my luggage, bedding, etc., searched when coming out of the valley of the Yungas.
"You are aware how I am looked upon as a doctor by the Indians. Well, one day I said, 'Manuel, I may some day require some seed and flowers of the famous white flower, Rogo cascarrilla, as a remedy; and I shall rely upon you not deceiving me in the way you have told me.' He merely said, 'Patron, if you ever require such seed and flowers, I will not deceive you. And I thought no more about it.
[203]"Manuel was never aware of my requiring seed and leaves for propagating purposes; he was always told they were wanted to make a special remedy for a special illness. For many years, since 1844, I had felt deeply interested in seeing Europe, and my own dear country in particular, free from being dependent on Peru or Bolivia for its supply of life-giving quinine. Remembering and relying on Manuel's promise to me in 1856, I resolved to do all in my power to obtain the very best cinchona seed produced in Bolivia.
"His son Santiago went to Australia with me in 1858. In 1861, the day before sending back to South America Santiago and the other Indians who had accompanied me there as shepherds of the alpacas, I bought 200 Spanish dollars, and said to him, 'You will give these to your father. Tell him I count on his keeping his promise to get me forty to fifty pounds of rogo cinchona (white flower) seed. He must get it from trees we had sat under together when trying to reach the Mamore river in 1851: to meet me at Tacna (Peru) by May, 1863. If not bringing pure, ripe[204] rogo seed, flowers, and leaves, never to look for me again.'
"I arrived back in Tacna on the 5th of January, 1865. I at once sent a message to Manuel, informing him of my arrival. At the end of May he arrived with his precious seed. It is only now, some twenty-four years after poor Manuel promised not to deceive me, manifest how faithfully and loyally he kept his promise. I say poor Manuel, because, as you know, he lost his life while trying to get another supply of the same class of seed for me in 1872-3. You are aware, too, how later on I lost another old Indian friend, poor Poli, when bringing seed and flowers in 1877.