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word implies, plant-animals, and this in a very real and 
extraordinary manner, for they maintained that the branch- 
ing stalks were of a vegetable nature, containing organisms 
of an animal nature. The theory of Pallas was supported 
by Linne and opposed by Ellis, and in the discussions on 
this question the Bryozoa were used as' much as any of the 
other zoophytes to show the vegetable nature of what we 
now know to be an integral part of this animal, which, 
together with other zoophytes previously to Ferato, had 
been thought to be merely plants.* 
Since then the Actinozoa have been separated, including 
animals, having one simple body cavity and divided by 
radiating calcareous or non-calcareous divisions; and the 
Bryozoa were shown by Milne Edwards, 1828; Thompson, 
1880; Ehrenberg, 1832, to vary considerably from the 
Hydrozoa in having a curved digestive system with two 
orifices: the first called them tunicated polyps, the second 
Polyzoa, and the third Bryozoa (moss animals). Since then 
additions have been made to our knowledge of these animals, 
and there have been many battles fought over them, and as 
there are many points unsettled, we may expect “wars and 
rumours of wars” for a long time. 
Many of the Hydrozoa in the external forms of their 
seaweed-like growth closely resemble the Bryozoa, but 
differ in having only a single cavity, and, unlike the Antho- 
zoa, have no radial divisions. 
The calcareous Algse are now under the care of the 
botanists, and do not require any further consideration 
from us. 
The economy of the animals now under consideration is 
in many respects as strange as anything in the animal 
kingdom, and we shall see that there are many points 
which show an external resemblance to plants. As men- 
# For the history of the Bryozoa see Johnstone’s Brit. Zoophytes ; 
Dr. Allman, Freshwater Polyzoa ; and Nitsehe, Beitrage zur Kenntniss 
der Bryozoen. 
