vi 
part of many living animals, united, and incapable of 
voluntary separation from each other. These animals, 
or polypi, have but one character in common, that 
of being continually attached to an animated mass, 
sharing in, and contributing to, its existence; and, not- 
withstanding this involuntary attachment to the colony, 
each individual possessing a life peculiar to itself, 
and distinct from the rest of the colony, all the polypi 
of a Polypidom participate in its existence ; and the 
food which one of these little creatures takes in, ex- 
tends its influence to the most distant part of the 
colony it belongs to. 
CLASSES, ORDERS, &c. 
The arrangement into Classes, Orders, Genera, and 
Species, so advantageously employed in Botany, has 
been adopted in the present work ; the Polypidoms 
are separated into four Classes, with the first of 
which we commence a sketch of our History. 
The first Class is that of the celluliferous Polypi- 
doms, whose polypi are found in shelly or non-irri- 
table cells ; it is divided into three Orders, begin- 
ning with that whose cells are apparently isolated ; 
