i88 A NATURALIST IN THE PACIFIC chap. 



C. bonduc is restricted to the interior. In Samoa, as we are in- 

 formed by Reinecke, C. bonducella is frequent both in the coast 

 districts and in the mountain-forests. In the Samoan mountains 

 the pods lose their prickles, and from this circumstance, as well as 

 from the extremely widespread distribution of the species over the 

 islands, the German botanist concludes that the plant has been for 

 ages established in the group. 



In Hawaii, Caesalpinia bonducella, which alone occurs, rarely 

 figures as a beach plant ; but it is found, as Hillebrand observes, in 

 the lower plains of all the islands. In the large island of Hawaii 

 I found it not on the scanty beaches of the coast, but on the 

 partly vegetated surface of the old lava-flows at distances varying 

 usually between a hundred yards and a mile from the sea, but 

 extending at times a few miles inland, and in one locality reaching 

 an elevation of 2,000 feet above the sea. It was mostly observed 

 by me on the dry side of the island, where, associated with Erythrina 

 monosperma, the Cactus, and the Castor-Oil plant, it thrives in 

 very arid localities, where the rainfall is only a few inches in the 

 year. Farther inland, where the old lava-surfaces were more 

 vegetated, it was associated with such shrubs as Osteomeles 

 anthyllidifolia and Cyathodes tameiameiae. Dr. Hillebrand, writing 

 of a generation and more ago, says that in his time the plant was 

 less common than formerly. 



The Methods of Dispersal of CcEsalpinia bo7idiicella and C. bonduc. 

 — We come now to the modes of dispersal of these plants ; and in 

 so doing we have to choose between the agencies of birds and of 

 currents. The seeds of C. bonducella are on the average -j^ of an 

 inch (18 mm.) in diameter, whilst those of C. bonduc are rather 

 smaller (^%- of an inch or 15 mm.). As far as their size and 

 character go, it would seem scarcely likely that birds could trans- 

 port these seeds across an ocean ; but our knowledge of the 

 agency of birds is of a very imperfect nature. Yet their occasional 

 dispersal by birds is not improbable. When I was in the Keeling 

 Islands the residents informed me that the seeds of C. bonducella 

 are sometimes found in the stomachs of sea-birds, such as frigate- 

 birds and boobies. (See Note 59.) 



However, it has long been known that the seeds of one or both 

 of these species are carried great distances by the currents ; but it 

 is to be gathered that the older botanists, in alluding to this fact, 

 more usually referred under the .synonym of Guilandina bonduc 

 to Caesalpinia bonducella. De Candolle, loth to attach much 

 importance to the effective transport of seeds by currents, was 



