Order Clxxvii
FLUVIALES.
With these the Vasculares and Monocotyledones terminate: it has long been apparent that we have been descending in the scale of vegetation; and hence, the last order exhibited a structure the most simple of all vascular plants. In the present order, Zostéra and Rúppia are so closely allied to Algæ, that they may be mistaken for them. 24 Zostéra L. 318 Rúppia W.
II. CELLULARES.
The characteristics of this division have already been explained in the preliminary observations upon the natural orders; and the remarks which were required for each natural order of Cellulares have already been given in Cryptogamia in the body of the work. It has, therefore, been thought advisable to adopt from Professor Agardh such observations as he has made upon the orders, as a sort of contrast to those already given. CLASS I. FOLIACEÆ.