26 



FOREST CONDITIONS OF PORTO RICO. 



For cordage. — Managua, a tall malvaceous bush. 



For dyeing- and tanning. — Moca, brasilete, achiote, granadillo, 

 maricao, dividivi, mora, gengibrillo, carnasey, vijao, mangle. 



Eesinous trees. — Tabanuco,i)ajuil, algarrobo, mamey, masa,cupey, 

 ruaria, guayaco. 



Forest trees yielding fruits. — Pma, nispero (medlar tree), 

 mango, guanabana, cocotero, aguacate, naranjo, jaeana, mamey, wild 

 orange. 



EXOGENOUS WOODS USED IN CONSTRUCTION AND OTHER INDUSTRIES. 



The writer, during his stay upon the island, collected sixteen speci- 

 mens of the native woods which are utilized by the people in construc- 

 tion and other industries. Fifteen of the woods are shown upon Pis. 

 VI, VII, VIII, the figures of which are printed directly from the woods 

 themselves. The descriptions of the woods are by Mr. George B. Sud- 

 worth, Dendrologist of the Division of Forestry. 



CHARACTERISTICS OF FIFTEEN PORTO RICAN WOODS. 



General description. 



Of the fifteen samples of Porto Rican woods examined, nine of them, 

 namely, mora, guayacau, hueso, ausubo, ucare negro, pata de caba, 

 ucare blanca, hachuelo, and algarrobo, were found to be very hard, 

 close grained, and heavy. The samples of equal size and of approxi- 

 mately the same condition vary but little in weight and are remarkably 

 similar in hardness. The following table shows the comparative weight 

 of the nine samples : 



Comparative weight of nine samples of Porto Bican woods. 



Name of wood. 



Mora 



Guayacau ... 



Hueso 



Ausubo 



TJcaro negro . 

 Pata de caba. 

 Ucare blanca 



Hachuelo 



Algarrobo . . . 



Weight 



per cubic 



foot. 



Pounds. 

 61.8 

 76.8 

 60.0 

 70.2 

 64.2 

 60.0 

 61.8 

 70.2 

 64.2 



Extreme density is shown by small pores (ducts) and in numerous, 

 minute, mostly continuous medullary rays, imperceptible to the naked 

 eye. The main structure is made up of thick-walled cells. The annual 

 layers of growth are small and comparatively indistinct, owing to the 

 irregular diffusion of the large ducts, which in most northern woods 



