IN SUMATRA. 251 



The ascent of the Ivarang-nata, as the principal peak is 

 called, was by no means easy, as its white cliffs — \\\\\r\\ from 

 below glinted prettily through the vcgetatiuu — were alnmst 

 perpendicular, and had to be scrambled up })y digging one's 

 fingers and toes well into the crevices. It has several caves full 

 of stalactites, one especially being of great dimensions, whose 

 numerous chambers were tenanted by thousands of bats, wlioso 

 stifling guano-like odour met me half-way down. The hill is 

 composed of a broad band of crystalline limestone bedded 

 between Devonian slates tilted up on edge, Avhich at the ))ase 

 of the hill run under the diluvium of the Palembang Plain. 

 The larger cave is in its interior quite protected from the severe 

 effects of the weather, but it bears evident traces of wlmt must, 

 I think, be attributed to sea erosion. The summit is a vast 

 rockery of disjointed blocks, with trees growing in the crevices, ^ 



their stems, as well as the crannies and faces of the rocks, 

 loaded with ferns and orchids {C^logyne, spp.) bearing trossos 

 of flowers more than a yard in length ; with various specius of 

 Me\istoma exhibiting bright flowers or pink fruits, but princi- 

 pally with a shrubby species, in great profusion, of Ctjrtandrem, 

 having a flower of a rich purple-blue colour, whicli to my great 

 satisfaction I perceived to belong to a new species, which I 

 have named Boea Tretilii* and probably to a new genus of. 

 that beautiful family. During the ten days— to my regret all 

 the time I could spare — of my stay in this region I made 

 large additions — some 200 species — to my herbarium amon 

 the specimens of trees, one being a species of nutmeg with 

 fruit as large as the largest orange. 



. Here, too, I noticed a singular case of ants milking a winged 

 Hemipteron, which of course could not l)e kept in caitfivity, 

 as they do many species of the wingless aphides. The 

 Hemipteron sat quietly, evidently enjoying the opprjition, and 

 at frequent intervals discharged a drop of matter, which was 

 eagerly sipped up by the ants. 



I have already spoken of the great beauty of the riverside 

 vegetation coming down the Rupit which ran through a 

 less great forest than that between Xapal Litjin and 3Iuara 



So named in honour of Dr. Melchior Treub, the esfeemed Director of the 

 Botanical Gardens in Buir3nz..rg, t* whose kind aid and influei.ce I owed 

 much during .ny stay in the Archipelago, 





