310 “THE ATLANTIC. [cHap. Iv. 
Fie. 84.—Concretions in Aolian Rock, Bermudas. 
is these tubes and threads of stalagmite which afterward in the 
pseudo-fossil represent the diverging rootlets. 
Sometimes, when two or more drops fall from stalactites 
close to one another, the cups coalesce (Figs. 80, 81, and 82); 
sometimes one drop of two is more frequent than the other, 
and then we have the form shown in Figs. 81 and 82; some- 
times many drops irregularly scattered form a large pool with 
its raised border, and a few drops more frequent and more 
constant than the rest grow their palmetto stems within its 
limits (Fig. 83); and sometimes a number of drops near one 
another make a curious regular pattern, with the partitions be- 
tween the recesses quite straight (Fig. 84). 
I have already referred to the rapid denudation which is go- 
ing on in these islands, and to the extent to which they have 
been denuded within comparatively recent times. The floors 
of caves, from their being cemented into a nearly homogene- 
ous mass by stalagmitic matter, are much harder than the ordi- 
nary porous blown limestone; and it seems that in many cases, 
after the rocks forming the walls and roof have been removed, 
disintegration has been at all events temporarily arrested by 
the floor. Where there is a flat surface of rock exposed any- 
