153 



Hence ; 



3,1 



4,1 

 5 



3,7 

 2,4 



These equations show as well as the general shape of the curves 

 that: 



if we compare the total number of plants with the number of 

 those that determine the vegetation, this latter number is relatively 

 smaller with the South American plants than with the indigenous 

 Antilles plants, smaller again with these than with the plants 

 growing in the Antilles and for these again smaller than with 

 the indigenous South American plants. 



So we conclude that the influence of the South American flora is 

 strongest; we saw (p. 139) that also numerically this influence 

 is stronger on the flora of the Dutch W. I. Islands than on that 

 of Portorico. 



Still I should conclude from what I have personally seen and 

 from the tables about the distribution of the Antilles plants and 

 of the purely South American ones, that the outward appearance 

 of the vegetation, in spite of the typical Cereus species which 

 are either indigenous or South American and indigenous plants 

 like Casearia bonairensis, Phyllanthus Euwensii, is chiefly due to 

 the Antilles plants. 



To this should be added, however, that among the typically South 

 American plants there are a number which, although they do 

 not form a typical part of the vegetation, still occur in particularly 

 interesting spots, those namely where culture has least intruded 

 and which ar most inaccessible. Such are : Triplaris coriacea, 

 Capparis linearis, Tecoma chrysantha, Capparis tenuisiliqua. 

 Now • these are exactly plants which occur in St. Martha and in 

 the part of South America which geologically (see p. 129) related 

 to the three Dutch Islands Curagao, Aruba and Bonaire. 



