F 73 



*"'- 



ANNOUNCEMENT. 



After several years of collection and herbarium work on the 

 plants of the insular, coastal and plain regions of Yucatan, being from 

 the start deeply impressed by the peculiarities most of the species 

 present in their habit characters, form of leaf, and their proneness to 

 variation for protective and adaptive purposes, I have been com- 

 pelled to settle upon some specific character which is not affected by 

 environmental influences in order to avoid the error of creating a 

 large number of species and varieties upon what I have become posi- 

 tive are but form distinctions due to the peculiar conditions present 

 in this region where the fittest are struggling for survival. The specific 

 character found to be constant has proven to be the fruit and especially 

 its seed, no matter how great a variation from the type and from the 

 species as found in other and more normal habitat the other charac- 

 ters may show. The reproductive characters must hold their truth to 

 the type in order that perpetuation of the species may result. 



Feeling confident that a positive specific character exists in the 

 fruit and seed of all species, and finding that this character is usually 

 the last to be adequately described in botanical publications, it is upon 

 this character that I have based the special features of this work. 



The enumeration of the species of this region will occupy the 

 whole of Volume III of the Botanical Series of these Publications, 

 the fascicles of which will appear from time to time as opportunity 

 permits without regard to the natural sequence of the orders, though 

 each natural order when issued will be complete as far as the knowl- 

 edge of our species obtains. 



