which exist in all parts of the frond, are rather more developed. These 
are, however, very unlike ¢etraspores. Colour dark brownish red. Sudstance 
cartilaginous. 
There is such a strong external resemblance between the sub- 
ject of this plate, and that of the following one (Polyides rotun- 
dus), that they are often mistaken one for the other, and without 
contrasting the fibrous root of the former, with the large scutate 
base of the latter, it might, m some instances, be difficult to 
discriminate between them. ‘There is, indeed, some difference 
in the structure of the frond, but not of a very striking character, 
and though easily observed when slices of both are seen together 
under the microscope, most difficult of beimg defined in intel- 
ligible words. And yet, with this resemblance in general ap- 
pearance, all modern authors, with the exception of Kiitzing, 
place them in different genera; and, until very lately, even in 
different families. This opinion of botanists is grounded on a 
great difference observed between the fructification of these 
plants; and is probably correct. But the fructification of Fur- 
cellaria is very imperfectly known, or if known, is of such an 
anomalous character that it is difficult to build upon it. The 
pod-lke elongations of the branches, which are produced in 
winter, and drop off as the season advances, do indeed appear 
like fructification, and are so described by authors. But their 
structure is widely different from that of the fruit of other Rho- 
dosperms ; and if they be entitled to the name of fruit, it must be 
of the conceptacular kind, for the spores which they contain im 
no respect resemble tetraspores. If my dissections be correct, 
they differ from other cellules only by being of a darker colour. 
They occupy no isolated portion of the frond, but are found, 
though of smaller size, in all its parts, extending in a stratum 
between the external and internal filaments of the periphery, 
between which they are the connecting links; being attached to 
both by one or other extremity. I shall be very glad of further 
information on the fructification of this plant, should any observer 
have detected ¢etraspores. 
Fig. 1. FuRcELLARIA FASTIGIATA. 2. Portion of a frond with inflated tips: 
—toth of the natural size. 3. A transverse, and 4, a longitudinal section 
of a “receptacle ” :—doth highly magnified. 
