INTRODUCTION 



The Island of Jamaica, the largest of the British West Indian 

 Islands, is 144 miles long and 30 to 40 miles broad. It lies 

 about 90 miles south of Cuba, and about 380 miles X.E. of 

 Honduras, the nearest part of the mainland. 



" Jamaica is remarkable for the limited area in which very 

 many species are found, and for the wonderful contrasts in 

 neighbouring districts in geological structure and soil, in 

 elevation, in rainfall and in temperature. 



"The Blue Mountains in the eastern end of the island 

 attain the highest elevations, rising to 7,423 feet. The distance 

 from the ridge to the coast on the north and south in a straight 

 line is about 20 miles. On the Blue Mountains and north to 

 the coast the north-east trade winds bring almost constant 

 rain throughout the year, the rainfall varying from 150 to 

 200 inches annually. From the rid^e to the south coast the 

 rainfall decreases, and as the Blue Mountains run not directly 

 west but inclined towards the north-west, and as the prevailing 

 winds are from the north-east, the result is a decrease in the 

 rainfall in travelling along the coast from Morant Point to 

 Kingston ; thus from Morant Point to Morant Bay there is a 

 rainfall from 70 to 55 inches annually, then a belt 50 to 40 inches, 

 and then for a considerable distance to Kingston and beyond, 

 35 to 30 inches. The slopes of the mountains are frequently 

 precipitous, and there may be great differences in elevation, in 

 moisture and temperature within short distances. For instance, 

 one may pass from the southern slopes of the John Crow Peak 

 of the Blue Mountains at about 5,500 feet, where xerophytic 

 conditions sometimes occur and often cold nights with tempera 

 ture down to 50 F., round the shoulder to the north, and 

 straight down 2000 feet to the Mabess River, where there is 

 almost constant rain, continual moisture from a perennial stream, 

 and a warm temperature at nights. The geological structure of 



