THE ORIGIN OF THE HAMMOCKS 193 



{Bursera gummifera) ; marlberry (Icacorea pani- 

 culata); prickly ash {Zanthoxylum clava-herculis); 

 sweet bay {Per sea borbonia); Forstiera porulosa; 

 Lantana involucrata, a large shrub, usually con- 

 fined to the hammocks, and Rapanea guianensis 

 or myrsine. To my surprise Ilex cassine and 

 Baccharis halimifolia, two shrubs or small trees 

 which ordinarily grow only in low ground, were 

 also found here. The bayberry (Myrica cerifera) is 

 common in low land, where it often becomes quite 

 a tree. A form of it grows in the pine woods and 

 here it had reached a height of five feet. Ximenia 

 americana, sometimes called hog plum, grows in 

 both pine and hammock land; in the latter as a 

 small tree, in the former as a low shrub. Here it 

 was six feet high. 



The new hammock growth here is so dense that 

 one entering it is at once concealed and lost to 

 view. This demonstrates well enough that the 

 poor thin soil of the pine woods is able to support 

 hammock trees and also that there is no lack of 

 planting. Usually the more abundant and vigor- 

 ous hammock growth is on the rocky ridges and 

 not on the level land. The ridges are freer of other 

 growth and offer more room, and fires are less 



