44 THE JOURNAL OF BOTANY 



Anguilla, and a few other islands are composed. This region is 

 hilly but not mountainous, yevy Httle being over 400 feet, and it 

 presents a smooth and gently undulating aspect like the chalk 

 hills of the Chilterns or the lower ranges of the Downs. The 

 lower layers of the formation are usually strongly impregnated 

 with sodium chloride. Many small islands such as Long Island 

 and Iguana Island lie off this part of the shore and are mostly 

 low ; sometimes with small cliffs of hard limestone cut about and 

 eroded by the Atlantic surge. This formation is termed the 

 Antigua Limestone. 



The south-west portion of the island is of volcanic origin ; its 

 date is uncertain, but it is certainly not a primary igneous rock. 

 There is abundant evidence at many parts of the coast of this 

 region to show that the volcanic matter was forced through 

 sedimentary rock. For instance, between English Harbour and 

 Falmouth Harbour, the two formations can be seen side by side, 

 the sedimentary strata having been upheaved and metamorphosed 

 by the intrusion of the igneous rock. There are no definite craters 

 to be found, though such inlets as English Harbour and Five 

 Islands Bay have been sometimes considered as such. 



The mountains here, though not often rising above 1,200 feet 

 (Boggy Peak, the highest, being only 1,360 feet), are bold and 

 rugged, showing the features of a mountain plateau worn by 

 erosion. The mountains are only scantily clothed with vege- 

 tation ; but the valleys, sheltered by their steep sides, are very 

 fertile, and, owing to their protection from the desiccating 

 influence of the Trade Wind, and to their comparatively good 

 rainfall, show a strong resemblance to those of moister islands 

 like Dominica and Trinidad. Many tropical products, such as 

 Vanilla and Cocoa, can be grown in them which could not exist in 

 other parts of the island. They are also enriched by soil washed 

 down from the surrounding heights. These mountains are 

 Andesitic in composition. 



The land between these two ranges of hills is called the 

 Central Plain. It is, however, very undulating, and is not of 

 homogeneous composition. It consists largely of clays, but is also 

 diversified by sandstones, gravel beds, and limestone, which last 

 forms the small hills found mainly in its north-western part. Its 

 origin and place in the geological history of Antigua are not 

 decided yet, but they must be settled by geologists and not by 

 botanists. Part of it is doubtless alluvial, but the tuff which 

 occurs is very probably older than the Antigua Limestone. The sur- 

 face is mostly covered by clay which is very heavy in the southern 

 part near Bendals. There are small ponds scattered through it at 

 intervals, and there is a small watercourse called Bendals stream 

 which allows the surplus water to run off after heavy rain, when 

 it may be quite swollen though usually it is very dry. 



Both the Central Plain and the Limestone district are largely 

 covered by sugar estates, sugar being almost the only crop whicli 

 can be grown with satisfaction under the prevailing climatic con- 

 ditions. 



