162 
The Ohio Naturalist. 
[Vol. II, No. 2, 
NOTES OF TRAVEL IN PORTO RICO. 
Robert F. Griggs. 
By its configuration, Porto Rico is divided into two parts very 
distinct from each other in almost every respect and of primary 
importance in all the affairs of the island. The north side, which 
comprises about two-thirds of the total area, is kept constantly 
wet with almost daily rains. On the south it has been known 
not to rain for a whole year in some places. On the north side 
grows an abundance of luxuriant, tropical vegetation ; on the 
south in many localities are barren hills covered only with scrub 
brush. But throughout the island there is great local variation 
in all the climatic and physical conditions. 
Along most of the north side there stretches a low, coast plain, 
out of which rise numberless, small, steep hills. This plain, 
everywhere well watered, is in most places very fertile, but in 
the vicinity of Vega Baja it becomes a sandy waste. This sand 
desert is one of the most peculiar places it has ever been my 
fortune to visit. There is no grass (turf-making grass is almost 
unknown in the tropics), neither are there large trees. Every- 
where are low bushes not much more than ten feet tall. The 
sand beneath them is bare in many places, but is covered in others 
with various forms of herbage, most of which, instead of being 
composed of desert forms, as would be expected, is made up of 
the most typical water-loving plants, among which, Sphagnum 
(two species) and Utricularia are noteworthy. Imagine, if you 
can, a sphagnum bog shading into loose sand in a distance of 
only ten feet with no change in level. The explanation of this 
peculiar fact is, however, not hard to find. The rainfall is so 
copious that wherever there is any means of holding it, the 
hydrophytes take hold and spread, themselves acting as water 
holders when once started, while in other places the water quickly 
soaks into the sand and leaves it as dry as ever. 
The plain on which this sand desert is located is separated in 
most places from the sea by low hills. It is very level and was 
probably once covered with water out of which projected many 
rocky islands— the limestone hills of to-day. These hills are a 
very characteristic feature of the country. From an incoming 
vessel they are plainly seen projecting like saw teeth all along the 
coast ; from an eminence back in the country they appear to 
have no system or regularity whatever, but stick up anywhere 
sharp and rugged as though shaken out of a dice box onto a 
board. Further inland they are closer together with no plain 
between, though in other respects like those of the coast. 
It is as though they were eroded when the sea stood lower than 
it does to-day, perhaps very much lower; then the valleys were 
