678 Part IV. Chapter 7. 
cattle, the country having every appearance of having been grassland for a 
long time. — 
Liguanea Plain and the Salt Pond District are covered with chaparral, 
which owes its presence to the much diminished rainfall on the south side 
of the island as compared with the almost daily rains on the north side. This 
meteorologic fact is reflected in the vegetation. The country is covered with 
the mesquite, Prosopis juliflora, \logwood, Haematoxylon campechianum, Yucca 
aloifolia, Pithecolobium unguis-cati, Inga vera, I. ingoides, Acacia farnesiana 
and other leguminous trees and shrubs, while such cacti, as Opuntia tuna, 
O. spinosissima, species of Cereus abound, together with Bromelia pinguin 
and other xerophytic types of plants. 
Limestone Sinks (Cockpit) Formation. The vegetation of the cockpits on account 
of the inaccessibility of the country has never been investigated thoroughly, and we know little 
out the associations of plants there. The cockpits, which are west of the Clarendon ridges, 
vary in depth from shallow, eircular, basin-like depressions surrounded by low mamillary hills to 
steep-side sinks often 500 feet deep. These are developed in the upper part of white limestone. 
Below is another white limestone, also soluble, but less pervious than the former, and below this 
again, nodular limestone, clays and conglomerates of the older insoluble and impervious strata 
which check the downward course of the lime-charged waters and force them to take a hori- 
zontal direction. When the bottoms of the cockpits reach the more resisting limestone of the 
second group, their perimeters begin to expand and round or oval valleys are formed known in 
Jamaica as light-holes. The flora of these sinks is peculiar and is still open to investigation. 
In the Great Morass of Westmoreland, according to BRITTON'), we have 
a swamp of large extent similar in some features to the Everglades of Flo- 
rida. The rare tree Crudia Schreberi (= C. spicata) grows here, as well, as 
the marsh cabbage palm Oreodora and a veritable forest of the long thatch 
palm Geonoma Swartziü. — 
The River Bank Formation is typically developed along the numerous 
streams in Jamaica, but as it insensibly merges into that of the tropic rain 
forest, it will be best to refer to it again under that head. Roaring River 
where it passes under the road from St. Ann’s Bay to Ocho Rios is a series 
of low waterfalls separated by nearly level stretches which present the curious 
aspect of many large trees (Bucida buceras, Grias cauliflora) growing directly 
in the water. Their seeds germinate in the calcareous travertine, or tufa, 
deposited in the level stretches from the water. (See plate XVIto page 672.) 
Tropic Forest Formation. This is typically developed ‘on the north side 
of the island and on the slopes and the summits of mountains where the rain- 
fall is sufficient to stimulate the growth of a rich and luxuriant vegetation. 
The whole eastern part of the island about the John Crow Mountains is one 
of very heavy rainfall and the vegetation is wonderfully varied and beautiful. 
Ferns according to CAMPBELL?) abound and in some places thickets of beautiful 
ı) Journal New York Botanical Garden IX: 83. 
2) CAMPBELL, D. H.: Botanical Aspects of Jamaica: see Bibliogr. p. 88; Jonnson, D. 5. 
A botanic Expedition to Jamaica. Johns Hopkins University Circular; new ser. 1907: 21. 
