many ways, while they nearly, or altogether coincide with his own 
group Spongites mn Melobesia. 
Under the preceeding plant I have mentioned that the vege- 
table nature of the Corallines is now distinctly proved. The 
question still remains, whether the productions here called JZe/o- 
besia (Nullipore, Lam.) are independent vegetables ; or whether 
they be, as has been held by several naturalists, merely amor- 
phous states of the common Corallina officinalis. 'This is the 
view of the subject advocated by Dr. Johnstone, whose opinion, 
founded on observation, and as the opinion of an accomplished 
naturalist who has paid much attention to the lower tribes of 
animals, and is familiar with variations in form among sponges, 
nearly as wild as this would be, must not be too hastily con- 
demned. In the present state of my acquaintance with these 
plants I do not feel myself warranted im giving a direct negative 
to Dr. Johnstone, although, so far as my opportunities enable me 
to judge, I am not disposed to agree with his view of the subject. 
Granting that the base of Corallina officinalis is a calcareous ex- 
pansion resembling the frond of a J/c/obesia, I cannot therefore 
suppose that objects, like that figured in our last plate, together 
with the minute Melobesia pustulata, found on the leaves of the 
Zostera, are merely such bases which have omitted to develope 
true fronds. It should be borne in mind that the A/elobesie 
have their proper organs of fructification, and that these are 
similar in nature to, though slightly different m form from, those 
of Corallina; and this I consider affords the strongest evidence 
of their independent nature, and the strongest probability of their 
being fully developed organisms. Still I will not say that it is 
conclusive evidence; for we must remember that in plants of 
greatly more perfect organization, the Orchidee@, more than one 
instance has occurred of floral organs so different in structure as 
to be referable to different genera, having been produced at dif- 
ferent times by the same root, and at last occurring together on 
the same stem! If such things happen among flowering plants, 
what may we not expect on the confines of the Vegetable Kingdom? 
Fig. 1, 2. MrLoBEsta EA ee different varieties :—the natural size. 3. 
A eee section. 4. A transverse section of a branchlet :—slightly 
magnified. . Cellular eee of which the frond is composed :—highly 
magnified. 
