"FEB. I90I. OBSERVATIONS ON INDIANA CAVES—FARRINGTON. 263 
as it is at right angles to 
the wall. Observation 
of the broken-end of 
any of the ‘‘leaves”’ of 
such a group of stalac- 
tites will show the man- 
ner of growth. (See 
Fig. 8.) Such growths 
are not formed by water 
trickling down acrevice, 
but from currents de- 
bouching over a lime- 
stone shelf. The shelf 
must project slightly 
and the current of water 
must be relatively large. 
There are first formed 
stalactites of the ordi- 
nary conicaltype. Then 
deposition is confined 
only to one side of the 
stalactite, the _ side, 
namely, over which the 
descending water flows. 
Growth takes place then 
Tica > Sinei Ne TeneR ae Se almost wholly in this 
direction and in the direction of length. A deposit is, however, also 
built up from the surface of the shelf by the water flowing over it. 
So the mass grows upward in a thin layér, downward at the 
stalactite points and outward in thin sheets-at right angles to the 
cave wall. There is also a slight lateral growth of the stalactites 
which causes them in time to join one another, and the group thus 
acquires the appearance of a continuous sheet thrown into folds. 
The original stalactite points usually continue to be the points of 
greatest growth in length, but the stalactite may be longest some 
distance away from these. Corrugations of the surface showing 
retardations of the flowing waters, and similar to those so common 
On icicles, are nearly always present. If the current is compara- 
tively narrow and maintains its position for a long period of time the 
Stalactitic mass will take a semi-circular form owing to the fact that 
the portions in the center of the current receive more material than 







