Malacology. 19 
its bones, because it has none to break; it has a 
shell, however, which may be broken, at least in 
some cases, for all Mollusks have not snug habita- 
tions of the kind; but wander about the watery or 
earthy world in which they live, quite naked ; such 
as the sea and land slugs, and some worms, leeches, 
etc.; but with these we have nothing to do, our 
present subject including only a part of 
MALACOLOGY, 
another member of that queer ology family, deriving 
its name from two Greek words signifying soft, and 
a discourse; hence it means a discourse upon soft, 
or soft-bodied animals, that is mollusca. It is only 
a part, then, of Malacology that we have to do 
with ; that part which relates to the shell-inhabiting 
mollusks, and strange creatures enough some of 
these are. We will have a look at them presently ; 
just now it will be sufficient to observe that the 
mollusca testacea, or soft-bodied animals, furnished 
with shells, possess the power of exuding, that is, 
discharging from various parts of their bodies a 
sticky kind of fluid, which mixing with the chalky 
matter collected from the water, and becoming hard, 
forms, in process of time, the shelly covering which 
is at once a dwelling and a defence for the inhabitant. 
