APPENDIX 



smooth, hairy, but never lepidote. But whatever be their nature, and 

 however great their variability, a Ficus can always easily be recognised 

 as such even by its leaves alone. 



All of them in Borneo have a white milky sap. As far as I know, 

 there is only one Ficus in Malaysia, F. leucantotoma, Poir., which has a 

 watery sap, but this species does not appear to have been as yet found in 

 Borneo. Those species which attain large dimensions always have a 

 light and soft white wood. 



Of the 55 species of Ficus which I have collected in Borneo, only 

 sixteen are apparently peculiar. What a difference from the palms, 

 of which only eighteen to twenty species out of 130 are found elsewhere, 

 even including the domesticated forms ! The explanation lies in the 

 fact of the facile dissemination of the various species of Ficus through 

 the agency of birds, an explanation which applies to all trees which 

 produce edible fruits specially relished by animals. The species of 

 Ficus preferred by birds, particularly pigeons, hornbills, and buccos, 

 are those belonging to the section Urostigma, which includes sixteen species 

 known to me in Borneo, of which only two are not found elsewhere. 

 On the other hand, of ten species belonging to the section Covellia, which 

 develop their fruit on the lower portion of the trunk or on underground 

 offshoots — in short in more or less hidden or inconspicuous positions, so 

 as to be with difficulty discovered by birds which are migratory, or of 

 powerful flight — six at least are peculiar. 



Such facts show that, in tropical countries, the various kinds of Ficus 

 are to a large extent biologically connected with birds, which perhaps 

 on their part also owe some of their peculiarities in the shape of the bill, 

 or in the plumage, to the nature and coloration of the fruits which form 

 their food. In the many bird-skins which passed through my hands 

 I have very often found that a relation existed between the colour of 

 the fat on their bodies and that of the fruits on which they habitually 

 fed. 



The Bornean figs have usually globose or pyriform fruits, the size 

 of which varies from that of a small pea to that of a large lemon (F. 

 callicarpa, Miq.). Exceptionally small is the fruit of F. linearis, Becc, 

 hardly one-eighth of an inch in diameter. Their colour is mostly yellow, 

 but red and even black are frequent. Such colours are easily seen by 

 birds. The fruits are generally fleshy and tasteless, though often 

 sweetish, and in only one instance acid (F. acidula, King). In most of 

 the species, and in all the Urostigmas, the fruits are placed in the axillae 

 of the leaves on the terminal branchlets. They are on the bigger branches 

 in F. acidula, King ; and on the trunk in F. Miquelii, King ; F. con- 

 densa, King ; and F. Hensleyana, King. No less than six species in 

 Borneo produce fruits half hidden in the ground, or inserted on hypogeal 

 flagelliform offshoots, which radiate from the base of the plant. Four 

 of these, viz., F. Beccarii, King ; F. stolonifera, King ; F. Treubii, 

 King ; F. uncinata, Becc. (P. B., No. 2458=F. geocarpa, Teysm. v. 

 uncinata, King), are peculiar to the island. 



With regard to the general geographical distribution of the Bornean 

 figs, it may be said that two-thirds of the species are also found in the 

 Malay Peninsula, in Java, or in Sumatra, or else that they are very 



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