266 REV. R. BARON ON THE 
as has been frequently remarked, of a suddenly congealed stormy 
sea. To the west of this tract again there rise two or three 
mountain-ranges running, with more or less continuity, almost 
the whole length of Madagascar, the highest and the most 
westerly of which rises about 4500 feet above the sea. And as 
there are three stages in the physical features of the country 
from the sea to the highest range of mountains, so there are, 
more or less corresponding with them, three botanical zones; for 
although there is no distinet break in the flora, it varies consi- 
derably according to elevation. Moreover, in a Region ranging 
through 12 degrees of latitude, it is not surprising if we find con- 
siderable variety in the character of its vegetation, according as 
we approach or recede from the equator. Notwithstanding this, 
however, the Region is substantially one. 
The soil, with the exception of the sandy littoral belt and 
alluvial deposits in the great Ankay and Antsibanaka plains and 
along the courses of the rivers, consists almost wholly of decom- 
posed rocks of the crystalline schist series, especially gneiss. 
Granite and basaltic rocks here and there also make their 
appearance *. 
The region is traversed by numerous short rivers which rise in 
the hillranges to the west. Many of these rivers, in their 
attempt to discharge themselves into the sea, form lagoons. 
These lagoons, which constitute so prominent a feature in the 
character of the east coast, exist almost continuously for & 
distance of about 300 miles. 
There is a copious supply of rain on the eastern side of Mada- 
gascar. "This is due to the south-east trade-winds, which, coming 
from the Indian Ocean, precipitate the greater part of the moisture 
with which they are laden on the forest-clad slopes before 
reaching the higher plateau of the island. The only statistics 
we have in regard to the rainfall of the Eastern Region are those 
given by Mr. Shaw for the year 1882. He says that at Tamatave 
the amount of rainfall for that year was 94°94 inches. There can 
be no doubt, however, that the Region generally possesses a much 
higher rainfall than any other part of the island, the probability 
being that the average annual fall reaches from 90 to 100 inches, 
or even more. 
* For further particulars of the Geology of the island see my paper, “ Notes 
on the Geology of Madagascar," in the * Quarterly Journal of the Geological 
Society ' (Vol. xlv. Part 2, No. 178). 
