AMBOINA. 389 



In the case of most Anthozoan corals, the stinging organs are 

 not powerful enough to make themselves felt through the skin of 

 the hands, but I have often felt my hands tingle after having been 

 employed in collecting corals, other than Millepora, on the reefs. 



In diving, the face and open eyes are brought close to the 

 corals at the moment that these are grasped and irritated, and it 

 seems possible that the eyes might become seriously inflamed 

 ' and injured by the action on them of the nettle-cells. I mention 

 the circumstance as a warning to collectors ; where Mille- 

 porids are present, great care should certainly be exercised. 



On the shore of the harbour of Amboina, coral reef rock occurs 

 raised many hundred feet above sea level, forming a steep hill- 

 slope. At the summit of the ridges so formed the rock stands 

 out here and there, weathered into fantastic pinnacles, with sur- 

 faces honeycombed by the action of rain, just as at Bermuda.* 



Some of the smaller trees growing on these ridges are 

 covered with the curious epiphytes, Myrmecodia armata and 

 Hydnopliytiim formicaum ; these are plants belonging to the 

 natural order Cinclwnacece. Both plants are associated in their 

 growth with certain species of ants ; as soon as the young 

 plants develop a stem, the ants gnaw at the base of this and 

 the irritation produced causes the stem to swell ; the ants con- 

 tinuing to irritate and excavate the swelling, it assumes a 

 globular form, and may become larger than a man's head. 



The globular mass contains within a labyrinth of chambers 

 and passages, which are occupied by the ants as their nest. The 

 walls of these chambers and the whole mass of the inflated 

 stem, retain their vitality and thrive, continuing to increase in 

 size with growth. From the surface of the rounded mass are 

 given off small twigs, bearing the leaves and flowers. 



It appears that this curious gall-like tumour on the stem 

 has become a normal condition of the plants, which cannot 

 thrive without the ants. In Myrmecodia armata the globular 

 mass is covered with spine-like excrescences. The trees I 

 referred to at Amboina, had these curious spine-covered masses 

 perched in every fork, and with them also the smooth surfaced 

 masses of a species of Hydnophytwm,. 



* See pages 21, 78, and 83. 



