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made to the corallines. The seaweeds of this group often bear 
a more or less striking resemblance to organisms of a very dif- 
ferent nature, namely to the corals —a resemblance that is due 
chiefly to the fact that both have the habit of secreting lime and 
becoming thereby equally hard and stone-like. The true corals 
have, for a century and a half, been generally conceded to belong 
to the animal kingdom; but the ‘ corallines,” as the word is 
ordinarily applied at the present day, are just as truly plants as 
any other seaweeds. This latter fact, however, has not been 
recognized for a century and a half; indeed, it is scarcely more 
than half a aed since the conviction that corallines are plants 
has become in way general among the students of marine 
life. The ex ent resemblances oe between these two 
groups of entirely different Ass ae naturally led to confusions 
in classification, so that the literature relating to corals and 
corallines is more or less nae up to about the middle of 
the Gee se Just as the naturalists of the sixteenth 
and seventeenth centuries believed sponges and corals to be 
plants, so most of their successors for the next hundred and fifty 
years went to the other extreme and insisted upon considering 
the coralline seaweeds to be animals or else relegated them to a 
doubtful half-way pigeon-hole under the delightfully non-com- 
mittal name of oe The learned cae Ellis in his 
‘Natural History of m curious and uncommon Zoophytes’ 
(arranged by Daniel nee and published in olen in 1786) 
makes the following remarks on the genus Corallina, which, as 
limited by him, consisted entirely of what we now know to be 
plants: ‘‘Is an animal growing in the form of a plant; whose 
stem is fixt to other bodies, and is composed of capillary tubes, 
whose extremities pass through a calcareous crust, and open into 
pores onthe surface. . . . This genus has been thought by some 
late writers to belong entirely to the vegetable kingdom, and to 
differ but little from Fucus’s and Conferva’s; but as Dr, Linnaeus 
observes, in a note on this genus in his System of Nature, p. 
1304: ‘Corallinas ad regnum animale sams ex substantia 
earum calcarea constat, cum omnem calcem animalium esse pro- 
ductum verissimum sit.’ Or, that all oo substances are 
