1063 



Ojc Eixas'urji at aSotaun. 



[siph 



frond funned of a single thread-shaped 

 branched cell, or of a number of such cells 

 united together into a spongy frond. It is 

 divisible into tw distinct suborders: in one 

 of which, Caulerpew, the main cell is filled 

 with a network of branching fibrils, amidst 

 which the minute zoospores are dispersed; 

 in the other, Qodiece, the filaments, which 

 may be either free or closely united into 

 a common frond, are filled with green 

 endochrome, and give rise here and there 

 to capsules which ultimately contain one 

 or more zoospores. The Caulerpece are all 

 inhabitants of warm coasts, but the Codiece 

 are often found in colder climates. In 

 either division we have species which are 

 truly aquatic or terrestrial, or at the least 

 amphibious. In the second division there 

 are many species, as for example those of 

 Ralimeda, which resemble corallines from 

 the quantity of carbonate of lime which en- 

 ters into their composition. In Vaucheria 

 and Bryopsis we have the threads whether 

 branched or single perfectly free, and in 

 Botrydium the vegetative part is reduced 

 to a minimum, and all that is visible is a 

 mass of bladdery capsules. [M. J. B.] 



SIPHONIA. To this genus we are in- 

 debted for the greater part of our supply 

 of Caoutchouc or India-rubber. It belongs 

 to the Euphorbiacece, and consists of some 

 half-dozen species, one of which, 8. elastica, 

 is a native of French Guiana, and the re- 

 mainder of the Amazon and Rio Negro 

 districts of Brazil. They are called Seringa- 

 trees by the Brazilians, from the Portu- 

 guese word seringa, signifying a syringe or 

 clyster-pipe, the caoutchouc having first 

 been used for making those articles ; and 



Si;>honia eiastica. 



the generic name, derived from the Greek 

 siphon, has reference to the same use. 

 The species are trees varying from twenty- 

 five to seventy or upwards of a hundred 

 feet in height, and all contain a milky 

 juice in more or less abundance, though 

 they do not all yield caoutchouc of good 

 quality, that from some of the species being 

 brittle. Their leaves consist of three en- 



tire leaflets radiating from the top of a 

 long stalk, and are clustered towards the 

 euds of the branches; and their flowers 

 arc borne in loosely-branched panicles.with 

 numerous little branchlets consisting of a 

 few male flowers and a female at the top. 

 Both sexes have a bell-shaped five-toothed 

 or five-parted calyx, and no corolla; the 

 males containing a central stamen-column 

 bearing five or ten anthers in one or two 

 series or whorls some distance below the 

 apex; and the females a three-celled ovary 

 bearing a more or less three-lobed, stigma 

 with or -without a short style. Their fruit 

 is a rather large capsule composed of three 

 one-seeded pieces, which split in halves 

 when ripe. The raw seeds are poisonous 

 to man and to quadrupeds, but macaws 

 i eat them greedily, and they are an excel- 

 j lent bait for fish ; long boiling, however, 

 . deprives them of their poison, and renders 

 them very palatable. 



The bulk of the Caoutchouc exported 

 from Para, whence our chief supply is 

 , derived, is obtained from 8. brasiliensis, 

 : which is the one common in the forests 

 j of the province of Para ; but that brought 

 I down to Para from the "Upper Amazon and 

 | Rib Negro is derived from 8. lutea and S, 

 brevifolia. These three species are all 

 j slender smooth-stemmed trees averaging 

 ! one hundred feet in height: the Para spe- 

 I cies, however, yields the greatest abun- 

 ' dance of caoutchouc. Europeans first be- 

 j came acquainted with caoutchouc in the 

 j early part of last century, and its botanical ■ 

 history was made known by M. de la Con- I 

 damine in 1736, but it is only within the I 

 ■ last forty or fifty years that it has become ', 

 j such an important article in our manufac- j 

 tures and commerce. It exists in the tree 

 in the form of a thin white milk, and is i 

 ! obtained by making incisions in the trunk, 

 ! from which it exudes and is collected in I 

 little earthen vessels, and afterwards con- 

 verted into the black homogeneous elastic 

 mass familiar to us as india-rubber, by 

 | pouring the milk upon moulds and imme- 

 diately holding them over the dense smoke 

 caused by burning the nuts of the Urucuri 

 \ palms (Attn lea excelsa and Cocos coronata) 

 ! until it is sufficiently hard to bear another i 

 ; coating, when the process is repeated un- I 

 { til the requisite thickness is obtained, and I 

 j the mould is then removed. Formerly j 

 j these moulds were always in the form of ! 

 shoes or bottles, and hence one of the 

 kinds of caoutchouc is known commer- 

 cially as bottle-rubber; but they are now 

 frequently shaped something like battle- 

 dores for folding linen, only thinner. In 

 1863 65,649 cwts. of caoutchouc were im- 

 ported into the United Kingdom. [A. S.] 



SIPHONODON. A name given by Grif- 

 fith to a tree from the Indian Archipelago, 

 which constitutes a genus agreeing in 

 most respects with the order Celastracece, 

 but very peculiar in the structure of its 

 pistil. The ovary, half immersed in the 

 calyx, has numerous uniovulate cells ar- 

 ranged in two or four series; and the co- 

 nical upper portion has a cavity at the 



