INTRODUCTION. SL 
Long had they been regarded as within the domain of the 
botanist. He laid claim to them as his subjects on various 
grounds. They often had the external appearance of little 
shrubs ;—they did not, like animals, move from place to place, 
but remained permanently in the same situation, attached to 
other objects by fibres much resembling roots of sea-plants. 
Some, from their hard and stony nature, were disposed to 
place them in the mineral kingdom, alleging that they either 
were crystallizations formed from calcareous sediment, or by 
some natural incrustation of seaweeds. In support of these 
theories more might have been adduced than at that time 
they were able to do. It is now found that what were called 
hthophytes, nullipores, and corallines, do really belong to 
the vegetable kingdom, — such as Janta rubens, Corallina 
officinalis, and the various Melobesie ; and as such they are 
figured and described in Harvey’s magnificent ‘ Phycologia.’ 
How they contrive to clothe themselves in these stony habi- 
iments, is one of the secrets of Nature known only to Him 
who can mix flint with the green integument of Hguisetum, 
and iron in the stems of some of our cereal grasses. That 
Jania rubens and the other nullipores, however, are of vege- 
table growth is no longer matter of conjecture, for on the 
application of a powerful acid their calcareous clothing is 
