FLORIDA REEFS. 59 
which time we have no evidence of any change in species, but, on the 
contrary, the strongest proof of the absolute permanence of those species 
whose past history we have been able to trace. 
Before leaving the subject of the coral reefs, I Avould add a few words on 
the succession of the different kinds of Polyp corals on a reef as compared 
with their structural rank and also with their succession in time, because we 
have here another of these correspondences of thought, those intellectual 
links in creation, which give such coherence and consistency to the whole 
and make it intelligible to man. 
The lowest in structure among the Polyps are not corals, but the single, soft- 
bodied Actiniaj. They have no solid parts, and are independent in their 
mode of existence, never forming communities, like the higher members of 
the class. It might at first seem strange that independence, considered a 
sign of superiority in the higher animals, should here be looked upon as a 
mark of inferiority. But independence may mean either simple isolation, or 
independence of action ; and the life of a single Polyp is no more indepen- 
dent in the sense of action than that of a community of Polyps. It is sim- 
ply not connected with or related to the life of any others. The mode of 
development of these animals tells us something of the relative inferiority 
and superiority of the single ones and of those that grow in communities. 
When the little Polyp coral — the Astroean or Madrepore, for instance — is born 
from the egg, it is as free as the Actinia, which remains free all its life. It is 
only at a later period, as its development goes on, that it becomes solidly 
attached to the ground, and begins its compound life by putting forth new 
beings like itself as buds from its side. Since we cannot suppose that the 
normal development of any being can have a retrograde action, we are justi- 
fied in believing that the loss of freedom is in fact a stage of progress in 
these lower animals, and their more intimate dependence on each other a 
sign of maturity. 
There are, however, structural features by which the relative superiority 
of these animals may be determined. In proportion as the number of their 
parts is limited and permanent, their structure is more complicated ; and the 
indefinite multiplication of identical parts is connected with inferiority of 
structure. Now in these lowest Polyps, the Actinias, the tentacles increase 
with age indefinitely, never ceasing to grow while life lasts, new chambers 
being constantly added to correspond with them, till it becomes impossible to 
count their numbers. Next to these come the true Fungidas. They are also 
