FERN GROTTOES OF FLORIDA 75 
County. After leaving the open pine woods which 
characterize most of the lime-sink region we traversed 
first a sandy hammock full of saw-palmetto, which did 
not look very promising for ferns; but just as we were 
about to conclude that we were on the wrong trail a 
few limestone rocks appeared, the saw-palmetto was 
left behind, and we were soon at the desired spot. 
It is difficult to describe the place satisfactorily. 
All the rock we saw was on two or three acres, at the 
edge of the river-swamp. It is a soft limestone, pre- 
sumably of the Vicksburg formation (Upper Eocene or 
Lower Oligocene, practically the oldest formation ex- 
posed in Florida), and has been dissected by the processes 
of weathering into rugged cliffs and chasms, the highest 
being perhaps ten feet above the water. Some rocks 
tumbling against one another as they were undermined 
by solution formed natural bridges, and there were 
also a few small caves. At the time of our visit the 
river was higher than usual, and backed up among the 
rocks, preventing exploration of any of the caves. 
e rocks were overgrown with a forest composed 
mostly of deciduous trees, such as Carpinus, Quercus 
Michauaii, Q. Schneckii, Ulmus Floridana, Celtis, Morus 
rubra, Liguidambar, Negundo, and Cornus florida, with 
Taxodium distichum and Acer rubrum in the wet hollows, 
the whole making a dense shade eight or nine months 
of the year. (They were already pretty well leafed 
out when we were there, the first week in March.) 
There were also two species of evergreen trees, Quercus 
Virginiana and Persea Borbonia, and some grape vines 
and other vines, but hardly any shrubs. The accom- 
panying illustration will give some idea of the aspect 
of the place, though the photograph was made under 
unfavorable conditions,with the bright sunlight coming 
through the forest canopy in spots. 
Ferns of all the species previously mentioned, as well 
as one or two others, were found growing all over the 
