IN BORNEAN FORESTS [chap. 



specimens of the largest known Calamus, and of the diminutive 

 Iguanura palmuncula, which is probably the smallest of known 

 palms. Its four or five fronds, which constitute the entire plant, 

 and are about the size of a man's hand, are borne at the summit of a 

 stem a few. inches high and of the thickness of a goose-quill. In this 

 same locality I collected at least twenty species of rotangs {Calamus), 

 and hence I named it the " Rotang Valley." Many a time I 

 lacerated my skin and tore my clothes in making herbarium speci- 

 mens of these plants, some of which have stems as thick as the wrist 

 and a couple of hundred feet in length, and are defended by a for- 

 midable array of thorns. 1 



On account of the difficulty in collecting and in preserving these 

 plants botanists usually content themselves with very imperfect 

 specimens, and do not keep the long filaments armed with hooked 

 spines which enable these rampant climbers to ascend and hold on 

 to trees ; nor do they preserve the leaf -sheaths which envelop the 

 stem and are the parts most covered with these thorns. Yet these are 

 precisely the parts which it is most essential to have and to study, 

 for they present the characters on which specific distinctions are 

 principally based, and by which the species of the genus Calamus ' 

 can be distinguished. 



It may be laid down as a general rule that when plants are pro- 

 vided with spines or thorns they possess nutritive qualities, and are 

 sought after by animals. The Calami, and other thorny palms, have 

 a central bud or " cabbage " (umbut) — a most delicate morsel, much 

 relished by many animals, monkeys amongst others ; and if this most 

 essential portion of the plant were not well defended, it would be 

 easily damaged or destroyed. 



In Borneo, except certain palms, the pandani, and some forest 

 Cyperaceae (Dapania and Scirpodendrori), which are also obliged 

 to defend their central buds, thorny plants are comparatively rare, 

 whilst they abound in those countries where ruminants are frequent. 

 There are, however, several kinds of spinous fruits in Borneo, such 

 as those of the durian and other BombacecB, the species of which 

 are so numerous on this great island. These fruits contain seeds 

 which are edible or surrounded by a pulp of agreeable flavour, and 

 are hence much sought after by various animals. 



It is, perhaps, not so easy to explain the relations which exist 

 between the nutrient qualities of an organ or a tissue in a plant and 

 the defensive thorns which are developed on it. My own opinion 

 is that these latter owe their first origin to the stimuli caused by 

 animals, especially by bites, punctures, and other lesions. In the 



1 Some authors have asserted that rotangs attain a length of 200 metres 

 (656 feet), but I cannot believe this possible. Loureiro, in his Flora 

 of Cochin China, describes his Calamus rudentum as having a stem " 500 et 

 lutra pedes longus ! " 



114 



