12 



north-east, it would seem that an estimate of 10,000 species for' 

 Borneo, for these two groups, would be a conservative one. 



The following comparative statement regarding the 

 approximate number of genera and species in the four families, 

 Gramineae.Piperaceae, Legiiminosae, Myrtaceae, for Borneo, the 

 Malay Peninsula, Java, and the Philippines, indicates that a 

 radical increase in the total number of Bornean species in each 

 may reasonably be expected, and what is true of these families 

 is at least approximately true of all large families of the 

 Bornean flora. 



GENERA. SPECIES. 



On account of our manifestly very incomplete knowledge 

 of the Bornean flora, it has not been considered expedient or 

 necessary to attempt to prepare analytical keys to the families, 

 genera, and species now known from Borneo; such keys, if 

 prepared, while they would serve as guides to the identification' 

 of most of the common and widely distributed species, would, 

 in all possibility, actually serve to identify not more than one- 

 half of the species that occur in Borneo. It is the task for 

 future botanists to prepare a general critical flora of Borneo, 

 and such an undertaking must, to be worthy of the name, be 

 based on immensely greater data and collections than are now 

 available. 



With the high percentage of endemism characteristic of 

 Borneo it is at once evident that published floras of surrounding 

 regions will serve the amateur or professional botanist chiefly 

 as guides to the generic identity of current Bornean collec- 

 tions, and to specific identifications only for those plants 

 of wide geographic distribution. A very high percentage of 

 any average Bornean collection must be identified either by 

 comparison with authentically named botanical material 

 preserved in various herbaria; by a study and comparison of 

 original Bornean descriptions; or by a combination of both 

 methods. There is no single published work that will aid the 

 investigator in the identification of more than a small percentage 

 of his current Bornean collections. The present list will serve 

 to indicate those species that are at present known from Borneo,. 



