413 
The structure of the reproductive organs of this order is so exceedingly 
variable that no common character seems deducible from them ; nor has it 
been found possible either to determine what analogy exists between the 
organs, or even to decide what their respective functions are. What are here 
called the thecae are considered to be the cases of the sporules, properly so 
called, but the other bodies are of a more doubtful kind. Those who have 
sought for sexual organs in Cryptogamous plants have naturally taken the 
imbedded oblong bodies of Marchantia, and the pedunculated reticulated ones 
of Jungermannia, for anthers ; but Hooker, in his beautiful Monograph of 
the latter genus, and also in his British Flora, (p. 459.) is evidently unsatis- 
fied as to their nature. Greville, in the Flora Edinensis, is clearly in a simi- 
lar state of uncertainty ; and Agardh admits nothing more in them than a 
resemblance to male organs, adopting the opinion that they are a particular 
form of gemmules. Mirbel considers the cups or baskets of Marchantia to be 
filled with little buds, and the peltate receptacles to be male flowers, while 
the stalked receptacles are masses of pistils. See his most admirable Memoir, 
tt. 6 et 7. The bodies lying in the cup- shaped receptacles of Anthoceros 
have been said to be anthers, but upon no good evidence. In Jungermannia 
there is a third kind of reproductive matter, consisting of heaped clusters 
of little amorphous bodies, growing from the surface of the leaves, and called 
gemmae. 
The most remarkable point of structure in Hepaticae is the spiral filament, 
as it is called, lying among the sporules within the theca. This consists of a 
single fibre, or of two, twisted spirally in difibrent directions, so as to cross 
each other, and contained within a very delicate, transparent, perishable tube. 
They have a strong elastic force, and have been supposed to be destined to 
aid in the dispersion of the sporules, — a most inadequate end for so curious 
and unusual an apparatus. It is more probable that they are destined to ful- 
fil, in the economy of these plants, some function of which we have no know- 
ledge. Hepaticae are intermediate between Mosses and Lichens, agreeing 
with the former in the presence of a distinct axis of growth. Fee says they 
have no calyptra, which must have been an oversight. They differ from 
Mosses in the want of an operculum, by which Andraea, which forms the link 
between Hepaticae and Mosses, is usually referred to the latter. Lichens are 
distinguished by their want of a distinct axis of growth, by their texture and 
colour, never assuming the rich lucid green of Hepaticae, and by their spo- 
rules not being contained in distinct thecae, but lying in membranous tubes or 
asci in the substance of the thallus. Riccia and Endocarpus form the con- 
nexion between them. 
The germination of this order takes place by an universal increase and 
enlargement of the spore, which becomes lobed as it were by the swelling of 
the cellules, and afterwards nourished by the emission of a radicular fibre. 
The original developement of Ferns and Hepaticae is much the same. FI. 
Bras. 1. 299. 
Geography. Natives of damp shady places in all climates ; two were 
found in Melville Island. The only atmospheric condition to which they 
cannot submit is excessive dryness; thus of the 237 species enumerated by 
Sprengel, 6 only are found in Africa, while 50 are cited from Java alone. 
Properties. Nothing is known of them. De Candolle thinks it pro- 
bable that the larger kinds will be found to resemble foliaceous Lichens in 
their qualities. A few are slightly fragrant. 
The following list was kindly furnished by Professor Nees von Esenbeck, 
December 1, 1835. 
