324 MOSTLY MAMMALS 
existence before the later Pliocene or early Pleistocene 
period. 
Caves of sufficient dimensions to have developed a special 
fauna of their own are met with in so many parts of the 
world, that it would be tedious to give a list even of those 
which are most generally known. Among those that have 
attained the widest degree of celebrity is the Mammoth 
Cave, situated in a hill of limestone in Edmonston County, 
a little to the south-west of the centre of Kentucky. This 
enormous cave is adorned with the most beautiful stalactitic 
and other deposits, which, when lit by the magnesium or 
the electric light, form an enchanting sight. Messrs. 
Packard and Putman write that “in the drier localities, 
where the floors are dusty and everything indicates the 
prolonged absence of moisture, the ceiling is covered with 
a white efflorescence, that displays itself in all manner of , 
beautiful shapes. It requires no stretch of the imagination 
to discover among these the perfect form of many flowers. 
The lily-form prevails, and the ceilings of many of the 
chambers are covered with this beautiful stucco-work, 
surpassing in delicacy and purity the most beautiful work- 
manship of man. These are not produced by the dripping 
of water, and the gradual deposit of sulphate of lime upon 
the outer portions. The stalactite is formed in this manner ; 
but these are neither stalactitiform nor are they produced 
in a similar way. ‘The efflorescence in the drier portions of 
the cave cannot take place where there is much moisture. 
The growth of these beautiful forms is from within, and the 
outer extremities are produced first. They are the result 
of a sweating process in the limestone, that forces the 
delicate filaments of which they are composed through 
the pores upon the surface of the rock, their beautiful 
curved forms resulting from unequal pressure at the base, 
