PREFACE. XXV 
Without having been able to trace their formation to 
the requisite early period, I think it will be found that 
the sporules are formed with the cells of the endothe- 
cum which have spiral fibres. It is by the separation 
of these with the sporule that the appearance of 4 fila- 
ments arises. 
The confervoid mass was, in the only species in 
which I have met with it, of considerable size, and al- 
ways inequilateral. The first sheath has no stomata. The 
others have, they occupy the fundi of depressions, and 
are arranged linearily on either side of the angles, 
which are opposite to the teeth of the sheaths. Their 
component cells present the peculiar appearance of 
transverse bars. The sheaths are not separable from 
the axis except the lower one, and the apices of the 
rest. 
Musci.—That the disk-like bodies produce, or are 
capable of producing young plants, as urged by some 
Botanists, is no proof that they originated from the 
male sacs. 
No one can doubt, that impregnation is effected in 
this family, the constantly simultaneous appearance 
and dehiscence of the anthers at the time when the 
pistilla are formed, the constant sphacelation of the 
style, and the subsequent evolution ot tne ':"^leus. or 
nucleary vesicle contained in the pistilla (or atleast in - 
that which produces the seta) are so much in common 
with the ordinary route of fecundation, that it is 
Scarcely possible to believe, but that an analogous me- 
thod is resorted. Here I may mention another fact 
of some importance, although occurring in Hepatice, —— 
