IN BORNEAN FORESTS [chap. 



of a superior quality. This the native name " laki," or " male," 

 would imply, being a term which Malays apply to trees, fruits, 

 or other objects excellent of their kind. The greater portion 

 of indiarubber of good quality, called " Ghetta janta-an sussu," is 

 produced in Sarawak by Willughbeia firma, and by Urnularia 

 oblongifolia, Stapf. (P.B., No. 2,272), and probably by other species 

 of these two genera, all of which when incised exude an abundant 

 milky juice, though only in a few does it coagulate, giving rise to 

 a product of commercial value. 



The eighteenth of August was a fine bright day, of which I took 

 advantage to finish the drying of the plants I had collected, arranging 

 them so that there might be no further danger with regard to their 

 preservation. A large number were already prepared ; these I tied 

 np in packages, and hung them up under the roof of the fort, so that 

 they might be safe from rats. Those still damp I also tied up, but 

 not so tightly, doubling the sheets of paper between the specimens. 

 I then hung them up in the Resident's kitchen over the fireplace, 

 but high enough to receive only a moderate heat. On my return 

 I found all of them in an excellent state of preservation. 



Towards dusk, on the banks of the Bintulu, I caught some 

 curious crustaceans and a small water snake. ,It was only after I 

 had been wading about for some time that I discovered that the 

 soft substance under my feet was not mud, but a sheet of vegetation 

 composed of a minute submerged plant hidden by a thin layer of 

 fine slush, so that it was not easily distinguishable at first. I after- 

 wards found that in some places it was uncovered and quite exposed. 

 This plant, which formed patches or small uniform meadows 

 uncovered at low tide, turned out to be an important botanical 

 novelty, Halophila Beccarii, Aschers. (in Nuovo Giom. Bot. Hal., 

 iii. p. 302), belonging to that scarce group of plants which live and 

 blossom in the sea. The flowers of this Halophila are very small, 

 composed of three petals of a whitish colour, veined and nearly 

 transparent. When I found them the corollas were open, having 

 evidently taken advantage of the low tide to expand their petals. 1 



1 This marine Phanerogam suggested to me some further points on the 

 difficulties which beset living organisms in the present epoch in their adapta- 

 tion to the surrounding medium. It is beyond doubt that the genera and 

 the species of Phanerogams which are now found living on the sea bottom, 

 all belonging to the Hydrocharidse and to the Najadse — plants which abound 

 in marshes — are derived from those which grow in fresh water ; but the number 

 of the former, compared to that of the latter, is indeed small, notwithstanding 

 that for an immeasurable period of time the seeds of an infinite number of 

 marsh-loving plants must beyond doubt have been carried to the sea and 

 deposited on its bottom. This means that only at one given epoch, and in 

 a very few cases, has the adaptation of a freshwater plant to life in salt water 

 been possible. If it were not so, the sea bottom would now be as well pro- 

 vided with plants and flowers as is the surface of dry land. There are few 

 cases in which so great a power of adaptability is needed as in the one under 



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