At Arica they occurred on the beach only. At Callao they also extended inland on the low spit at Punta for about 100 yards. At Ancon they were found not only on the beach but also twenty or thirty paces inland on the low adjoining plains. Their size varied from three inches to three feet. They were all more or less rounded by wave action, and were extensively burrowed by boring molluscs. Whilst some on the beach still displayed the dried-up soft parts of the boring mollusc, others inland were falling to pieces and undergoing chemical change. There was nothing to indicate that the corals were recently alive; and at Ancon they appeared to have been torn off a rocky spit of andesite that had become exposed on the beach during a recent movement of emergence, of which there is other evidence on this coast. Further particulars are given on page [496].
NOTE 76 (page [429])
Stranded Pumice on English and Scandinavian Beaches
Sernander, in his description of the Atlantic drift of the Scandinavian coast, refers to the occurrence of a small amount of true pumice. I have found solitary fragments of acid pumice well rounded by wave-action at Croyde Bay on the north coast of Devonshire, at the mouth of Salcombe Harbour on the south coast of the same county, and at Maenporth, near Falmouth, in Cornwall. Steamer slag, in some cases rudely simulating pumice, is common on all the South of England beaches I have examined. It is also common on the Scandinavian coasts, though seemingly regarded by Helge Bäckström, who is quoted by Sernander, as derived from the factories on the east coast of England. (See on these subjects a paper by Helge Bäckström, “Über angeschwemmte Bimsteine und Schlacken der nordeuropäischen Küsten”; Bihang till K. Sv. V. A. Handl. Bd. 16. Afd. 3, 1890; also a letter in Nature, about 1886, by H. B. Guppy.)
NOTE 77 (page [21])
On the Mode of Dispersal of Kleinhovia hospita
This small tree has a very wide distribution in the tropics, ranging from East Africa and the Mascarene Islands through India, South-eastern Asia, Malaya, New Guinea, and the Solomon Islands to Fiji and Tahiti. It is a plant that grows in inland open woods as well as amongst the littoral trees on the beach; and it is always doubtful (in Malaya, Fiji, and Samoa) whether to regard it as a shore plant or as an inland plant, different authors varying on this point. In Vanua Levu I formed the opinion that it is only an intruder amongst the littoral vegetation. In accounting for its distribution we have to choose between man, the bird, and the current. Though it may sometimes be noticed in native plantations, as I observed in the Solomon Islands, the tree has no special use; and the Solomon Island natives themselves indicated to me that the parrots that fed on the fruits of the tree aided in distributing the plant. The buoyant behaviour of the seeds, which are freed by the dehiscence of the bladder-capsules on the tree, is not constant. Whilst in the case of the seeds of littoral trees in Fiji I found that 30 per cent. floated after ten weeks, Prof. Schimper ascertained in the case (seemingly) of Malayan seeds that they sank at once. The seed-structure connected with the buoyancy is, as shown on page [105], accidental in character, and reference is made on page [20] to other plants of doubtful littoral reputation, in which the buoyant qualities are variable. The occasional buoyancy of its seeds will only, as I think, explain its occasional station at the coast; and I agree with Prof. Schimper (p. 156) when he attributes its wide distribution to birds, the seeds being hard, crustaceous, and about three millimetres across.
NOTE 78 (page [436])
On the “Sea”: an Unidentified Wild Fruit-tree in Fiji
This is a fair-sized forest tree common in places in the lower forests. I have never been able to identify it; but a “putamen” which was sent to the Kew Museum was named Spondias with a query. It is to be hoped its true botanical name will be discovered by one of my successors. Seemann places it amongst the “desiderata” concerning which further information is needed. The fruit is a drupe 2 to 21⁄2 inches long possessing a pleasant fruity odour and inclosing a hard two-celled stone about 12⁄3 inch long, one cell containing a large fleshy seed covered with tawny hair, the other filled with the hair only and containing no seed. The Fijians say that these fruits, large as they are, are swallowed by the fruit-pigeons, the stones being found in their gullet. The leaves are distichous, alternate, lanceolate, eight or nine inches long, glabrous and dark green above, and covered below with a whitish woolly matted tomentum. The empty stones are not uncommon in the stranded beach-drift.
NOTE 79 (page [395])
On Willow-leaved River-side Plants
A number of observers, beginning with Humboldt, in his Ansichten der Nature, and including Seemann, L. H. Grindon, Ridley, Beccari, and others, have referred to what is called “stenophyllism” in plants. These willow-leaved river-side plants are found all over the globe, such plants usually growing close to the water’s edge in situations where they are liable to be more or less submerged when the river is in flood. Seemann, Beccari, and Ridley mention more than two dozen genera belonging to a great variety of orders, and including Acalypha, Antidesma, Calophyllum, Eulalia, Eugenia, Fagræa, Ficus, Garcinia, Ixora, Lindenia, Melastoma, Podocarpus, Psychotria, &c., all tropical, and represented either in Fiji, Borneo, or in the Malay Peninsula; whilst my readers will recall amongst temperate floras river-side plants of the genera Epilobium, Lythrum, Salix, &c., possessing the same form of leaf and the same station. The genus Eugenia comes under this category in Fiji, Borneo, and the Malay Peninsula, with reference to one or more of the species. In Fiji, species belonging to the genera Lindenia and Dolicholobium especially attracted my attention in this respect. It is noteworthy that several of the Bornean plants and some of the Fijian plants here concerned are endemic. Just as I have remarked in the question of the buoyancy of seeds and fruits, that not all water-side plants have buoyant seeds or fruits, but that nearly all plants thus endowed are found at the water-side, so we may say of the willow-leaved plants, that not all river-side plants have the willow-form of leaf, but that plants thus characterised gather at the river-side. Beccari and Ridley regard this willow-form of leaf as the result of adaptation. Seemann remarks that we have here the old question whether the webbed feet of a duck are the cause or the effect of the bird’s swimming; and I take the same position. (See Seemann’s Flora Vitiensis; Ridley in Trans. Linn. Soc. Bot., vol. iii. 1888-94; and Beccari’s Nelle Foreste di Borneo, 1902, or the English edition of 1904.)