466 Mr. VALENTINE on the Development of the Theca, 
often mixed with jointed pellucid filaments, “ fila succulenta” of Hedwig, and 
in some cases accompanied by the supposed stamens, which in others grow 
on a different part of the same plant (monececious), or on a distinct plant 
(dicecious). The object of this paper is chiefly to explain the anatomy of 
these pistilla, their structure being such as to throw considerable light upon 
the sexual theory. I was first led to examine this subject by discovering the 
highly curious fact, that the setze of Mosses and the Jungermannias terminate 
downwards in a cone, which is inserted within a corresponding cavity of the 
branch, to which it has but a very slender attachment ; or, in other words, that 
the seta has very little if any organic connexion with the plant. This struc- 
ture appeared to be so anomalous, that I determined on the first opportunity 
to investigate the cause. The following observations are the result*. 
In the very young state the pistillum contains a single unconnected oval 
transparent body or cell, which is situated about one third from the base. 
The pistillum, as yet, has not begun to enlarge, but is of one uniform diame- 
ter. The cell is present before the apex of the pistillum has burst open to 
form the stigma; and consequently before there is any communication, by 
means of the tubular style, with the external air. This canal, however, is 
formed before the bursting open of the apex, and leads directly down to the 
cell, which appears to be situated in its lower extremity. The cell may be 
distinguished through the walls of the pistillum with the assistance of a good 
Wollaston doublet, and I have succeeded in dissecting it out uninjured. It 
was of a firm texture, a quality depending probably on the thickness of the 
membrane; it was also beautifully pellucid, and contained a quantity of 
moving particles. Upon pressing it with a piece of tale it burst, and the 
moving particles escaped. Its diameter was between the one thousandth and 
the one five-thousandth of an inch. Generally one or two only of the pistilla 
in the same bud arrive at perfection, and the abortive ones are destitute of 
this cell; whilst, on the contrary, in Bryum ligulatum nearly all the pistilla, 
sometimes amounting to between. twenty and thirty, become fruit, and in 
every one of them may the cell be detected. Bryum roseum very rarely 
* Since this was written, I have been favoured by Mr. Brown with a sight of Hedwig’s Fundamentum 
Historie, &c., in which this structure is figured. It is surprising that this remarkable peculiarity should 
not be anywhere noticed, either by Hooker, Greville, or, indeed, any of the British muscologists. 
