The Zoophytes. 301 
The modern fundamental conception of a Zoophyte, 
is a growth composed of lowly organised animal forms 
which have budded or grown one from another, and have 
remained organically connected with each other to make 
up a more or less plant-like colony. The most typical 
Zoophytes, as considered by the older naturalists, were 
organisms of this kind ; and this gives a sufficient justifica- 
tion for the restriction of the term " Zoophyte" to those 
related animals in which, while the typical colony is 
essentially plant-like in form, the parent or individual 
beings, which make up the colony, consist of a simple 
bag-like body usually furnished with radiate grasping 
organs, or tentacles, around the open end — beings 
which thus present a somewhat flower-like aspect. 
This bag-like body is never unicellular, and it is 
thus unlike to, and higher in organisation than, the 
typical forms of the Animalcules ; but it consists 
chiefly of two distinct layers of cells, or separate 
minute masses of protoplasm or albuminous substance, 
an inner and an outer. The outer layer of cells, 
always in intimate relation with the fluid medium 
in which the Zoophyte lives, is the seat of all sensa- 
tion and motion ; while the inner layer is the seat 
of the digestive functions, and lines the hollow of the 
bag which here takes the place of a stomach — the open 
end of the bag, usually surrounded by a circlet of arm- 
like feelers or grasping organs provided with stinging 
cells, serving as a true mouth and also as an aperture 
for the discharge of refuse matter. 
All the Zoophytes are capable of being reduced to 
this structural plan, the colony being simply aggregates 
of this type, its form being determined by the manner 
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