vi PREFACE. 



tree-growth. He finds that in the wood of one species at least, the 

 Black Mangrove, Avicennia nitida, there are no medullary rays that 

 extend from year to year, such as he was familiar with in woods in 

 general ; and furthermore that its annual rings, if such they may be, 

 are not continuous at all but very much broken and sometimes even 

 with ends overlapping. In another wood, that of the Strong-back, 

 Bourreria kavanensis, there is a remarkable intermingling of a firm 

 wood tissue and a very frail pith-like tissue, at variance again with his 

 ideas of wood-structure as ordinarily understood. 



The woods of twenty-five species of these tropical trees have been 

 collected and are shown in the illustrative specimens of this volume. 

 After an extended experience in collecting and sectioning woods, 

 covering now over three hundred species, for use in AMERICAN WOODS 

 (See announcement at the close of this volume), the writer has not, 

 in all of them together, found as many surprises in unusual structures, 

 etc., as he has found in gathering those for this volume. Of a few of 

 them it was found impossible to make transverse sections suitable for 

 use, owing to their brittle nature. Of others we were unable to make 

 sections of the standard thickness adopted in AMERICAN WOODS, but 

 we could make them thinner. A few of the transverse sections we 

 have had to reduce in size, and the very thin ones we have had to protect 

 with celluloid or mica on account of their fragile nature. 



In the preparation of this work I wish to gratefully acknowledge 

 assistance in the field-work by Dr. John Gifford, of Cocoanut Grove, 

 Florida, to whom it is my pleasure to dedicate the volume. For 

 information on the colloquial names in foreign languages by which 

 these trees are known in the tropics I wish to express my gratitude to 

 Dr. H. Pittier, Mr. C. D. Mell, and Dr. C. F. Millspaugh. 



LOWVILLE, N. Y., Nov. 28, 1913. 



