MISCELLANEOUS PLANTS 



243 



and they are much too fragile for transport over the sea. It is 

 possible that strong winds might carry the seeds some distance; 

 but experiment showed that this would not be greater than 100 

 feet in a moderate gale. 



Symphonia globulifera (L. fil.) 

 (syn. Moronobea coccinea, Aubl. Mart.) 



This West African tree of Upper and Lower Guinea is found in 

 the New World in Jamaica, Dominica, Trinidad, Guiana, North 

 Brazil, Panama, etc. Its station is by the riverside in mountain 

 woods, and in the swampy ground bordering estuaries, but above 

 the mangrove formation. In Jamaica I observed it flourishing at 

 the waterside on the banks of the Black River estuary ; and accord- 

 ing to Forrest Shreve, as quoted by Harshberger (p. 679), it grows 

 in the forests of the Blue Mountain Range, forming with Calophyllum 

 calaba and other trees closed arches over the rivers. The genus 

 has a remarkable distribution, though it may be in part explained 

 by our better acquaintance with the floras of some localities than 

 of others. Of its dozen or more known species nearly all are peculiar 

 to Madagascar; but two are West African, and one of these, S. 

 globulifera, is the widely spread New World species that we are now 

 considering. 



Its germinating seeds occurred in abundance in the floating drift 

 of the Black River estuary. In Jamaica it is known as " Hog-gum " 

 or " Boar- wood." Its softish, baccate fruits, which have a yellow 

 juice, are one-and-a-half to one-and-three-quarters of an inch long, and 

 hold from one to three seeds, one to one-and-a-quarter inch in length, 

 which are at first fleshy and afterwards tough and flexible. The 

 mature seeds, when freed by the decay or breaking down of the fruit, 

 are not in any way protected by their coverings against drying 

 or against the penetration of water; and when removed from the 

 fruit they shrink greatly. Their readiness to germinate, whilst 

 afloat in the Black River, is thus explained ; and I may state that 

 quite 95 per cent, of the seeds there observed were germinating. 



The seed presents the structure characteristic of several other 

 genera of the Guttiferce, a structure also illustrated in the Barringtonice. 

 There is a central axis separated from the outer thick portion by 

 a thin layer of vascular tissue (Mirbel's membrane), which becomes 

 wavy or crumpled in the drying seed. The cotyledons are either 

 absent or are represented by minute scales, the seed being, therefore, 

 merely an enlarged hypocotyl. 



When we reflect on the unprotected condition of the fruit and its 

 seeds, on the fleeting vitality of the seeds, on their readiness to 

 germinate when afloat in river-drift, and on the fate that must 

 await them when they reach the sea, it is not possible to find an 

 explanation of the plant's distribution on the opposite sides of the 

 Atlantic in dispersal by currents; and it would be equally futile 

 to look to the agency of birds. We may even go further and hold 

 that the seeds are not even suited for inter-island dispersal by either 

 agency in the West Indian region. Taking the arrangement of 



