Mr. J. Miers on the genera Hyoscyamus and Physochlena. 467 
XLI.—On Hyoscyamus and Physochlena. 
By Joun Miers, Esq., F.R.S., F.LS. 
HyoscyAMvs. 
I am induced to offer a few remarks, and propose an emended 
character for this genus, in order to confirm some observations 
made on a previous occasion (Auj. oper. ili. 174). Although the 
opercular dehiscence of the capsule of Hyoscyamus has long been 
notorious, the fact of a glandular enlargement on the summit of 
the ovarium does not appear to have been anywhere described : 
it is however a circumstance worthy of consideration in a physio- 
logical point of view, and leads us to inquire what is its true 
nature. In the ovarium of Hyoscyamus pictus, which I examined 
in aliving state, this glandular appendage is seen to form a very 
distinct, thick, and fleshy covering over its larger superior moiety, 
where it is terminated by a decided margin, and as the ovarium 
advances towards maturity, the lower portion increases consider- 
ably in bulk, the pericarpial envelope being drawn out to a thin 
membranaceous tube, marked with numerous longitudinal and 
branching nervures, while the upper thickened moiety increases 
but little in length : these longitudinal nervures may be distinctly 
traced upon the inner lining from the base to the summit of the 
cell, while upon the external face they are visible only on the lower 
portion, no trace of them being seen upon the glandular moiety, 
which exhibits quite a different texture, proving beyond all doubt 
that the glandular coating in question is really superimposed, and 
forms no part of the endocarpial lining, and therefore that it is not 
an interior secretion within the cavity of the cell. It is evident 
that the lower half of the ovarium consists of two cohering inte- 
euments with little or no intervening substance; for wien the 
fruit is ripe they are seen to be really distinct, and may without 
difficulty be separated from each other on their lacerated edges : 
but in the upper moiety the remarkable fleshy gland before men- 
tioned is seen to be interposed between the continuation of these 
two integuments, and as it hardens by the deposition of woody 
matter it constitutes the well-known operculum, which forms quite 
an external mushroom-headed enlargement, and which falls off, 
not bya regular dehiscence, but by a ruptured edge, as is proved 
by the lacerated margin of the two integuments upon the cir- 
cumscissile line. The nature and purport of this apical gland 
do not appear manifest ; it is probably an extension from the 
base of the style, for the epicarpial integument terminates at the 
summit of the ovarium by a small ring, that forms an apparent 
articulation with the style, which on the contrary is continuous 
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