MISCELLANEOUS PLANTS 



205 



and one Philippine species, the most important difference between 

 the two genera being that Crudya, unlike the other genus, has no 

 species common to both the American and African sides of the 

 tropical Atlantic. This difference is associated with the fact that 

 when we compare the two species of these genera that are most 

 likely to be dispersed by the currents, Chrysobalanus icaco of the 

 seashore and Crudya spicaia of the fresh-water morass of the lower 

 levels, the only one that could perform an ocean traverse through 

 the agency of its floating fruits or seeds is Chrysobalanus icaco, the 

 West African shore plant. But even here the traverse of the ocean 

 is restricted by the limited floating capacities of the fruit to the 

 passage in the Main Equatorial Current from the Gulf of Guinea to 

 Brazil. 



The distribution in the West Indies of the trees of the genus 

 Crudya, as indicated by Grisebach, is very interesting and provokes 

 inquiry. Three species are named, of which two are described as 

 frequenting swampy districts; whilst the station of the third is not 

 mentioned. All occur in the Guianas, one of them (the species 

 under consideration) being found also in Jamaica and the other two 

 also in Trinidad. 



It is with the species at home both in Jamaica and Guiana, namely, 

 Crudya spicata, that we are specially concerned, though it is highly 

 probable that the general features of its behaviour will be reproduced 

 by the other two species. This tree raises all the questions presented 

 by Symphonia globulij era (p. 243) and Grias cauliflora (p. 211). It 

 is especially comparable with the first named, since both occur in 

 Guiana. All three plants are trees of the riverside. In all three 

 cases the trees add their fruits or seeds to the floating river-drift, 

 and in all three cases the floating fruit or seed is usually found in 

 the germinating condition. In not one of these three trees do the 

 means of dispersal explain the presence of the same, or, as in the 

 case of Grias, of closely allied species in the large West Indian islands 

 and in the South American mainland. All three species are in the 

 same sense "difficult" plants. They are all of the greatest signifi- 

 cance to the student of distribution, and in all of them he is forced 

 to admit that " means of dispersal " do not explain " range." 



Crudya spicata, according to Grisebach, flourishes in the great 

 morass of Westmoreland in Jamaica, and Britton has more recently 

 referred to it in the same locality (Harshberger, p. 678). I found it 

 in that district on the banks of the Cabarita River in association 

 with Grias cauliflora. It also came under my notice on the banks 

 of the Black River near Lacovia. The flat ligneous legume, which 

 is about inches long and tardily dehiscent, contains one or two 

 large seeds which possess only thin, pervious, membranous coverings 

 that afford no protection against drying and but little against the 

 penetration of water. The pods are to be seen afloat in the river- 

 drift as well as the seeds ; the last owing their buoyancy to a large 

 central cavity between the flat cotyledons, the embryo itself having 

 no floating power. When the seeds occur in the floating drift, they 

 look rather like those of Entada scandens, and the Black River people 

 give them the same name of " Cacoon " ; but they are readily dis- 



