406 
Affinities. In Salvinia and AzoUa, the only kno^Yn genera of this 
order ; the vegetation is that of Mosses, or of Jungermannia, but the organs 
of reproduction are quite different. The latter consist of two sorts of mem- 
branous bags, of which one contains bodies analogous to the larger bodies, or 
thecae of Marsilea, and the other what have been considered male organs. 
These, in Salvinia, have been described by Brongniart as spherical grains, 
attached by long stalks to a central column, and much smaller than what he 
calls the seeds : their surface is reticulated in a similar manner, and they only 
burst by the action of water. In AzoUa, Ferdinand Bauer represents, and 
Brown describes, them as from 6 to 9 in number, angular and inserted upon 
a central* body, occupying the upper half of the involucrum, the lower being 
filled with a turbid fluid. If the real nature of these parts in PUularia and Mar- 
silea is involved in obscurity, that of the reproductive organs of Sal^dnia and 
AzoUa is stiU more mysterious. Brown, who had good opportunities of 
studying AzoUa in New HoUand, with Ferdinand Bauer’s acuteness and pro- 
found knowledge of structure to assist him, could arrive at no certain con- 
clusion. Martins, in whose work on the Cr 5 q)togamic Plants of BrazU, 
AzoUa is beautifuUy iUustrated, is of opinion that there is no ground for con- 
sidering one of the reproductive bodies male and the other female ; on the 
contrary, he suspects that the so caUed male body is an organ intended for 
developing the rudiment of a new plant ; /. c. 127. The involute vernation 
of the leaves of some of these plants and their involucre being formed 
out of the involute frond, as in Ophioglossum, indicate a close affinity to 
Ferns ; but the habit of AzoUa is rather that of some Hepaticse. MarsUeaceae 
may be considered to occupy an intermediate position between these tribes. 
Authors have not stated whether ducts are to be found in PUularia, Salvinia, 
and AzoUa ; they are present in abundance in Marsilea, where I have seen 
them ; but they are so minute as to require to be magnified 200 times to be 
distinctly observed. 
GENERA. 
Salvinia, Guett. 
Azolla, Lam. 
Alliance III. MUSCALES. 
Cellulares foliages, DC. Thtor. Elem. 249. (1819). — PsEUDocoTYLEDONEiE, Class I. 
Agardh. Aph. 103. (1822). — Heteronemea, Fries Syst. Orb. Veg. 33. (1825) in 
part. — Acotyledones, Class 2. Ad. Brongniart in Diet. Class. 5. 159. (1824). — 
Cryptogamic.®, 2d Circle, T. F. L.Neesv. Esenbeck and Eber7naier Handb. der Med. 
Bot. 1. 18. (1830). 
Essential Character. — Flowerless plants, with a distinct stem having no vascular 
system, but frequently furnished with leaves ; their sporules having a proper integument, 
and contained in distinct axillary, terminal, or superficial thecae. Germinating processes 
uniting into a heterogeneous body. 
These are altogether intermediate between the two first and the fifth affi- 
ances, and are distinguishable essentiaUy by their having a distinct axis of 
growth without any vascular system ; they are connected with MarsUeace8e 
by Jungermannia, and with Lichens by Riccia and Marchantia ; to Algae the 
transition is by Characeae, which have the evascular axis of Muscales, with 
the habit and propagating matter of Algae. 
