Botanical Society of Edinburgh. 425 
dulosus) having ‘‘ caule summo pedunculisque glanduloso-hispidis,” 
which we believe to be the plant before us and that found by Mr. 
Hardy. Of the above characters the gland-tipped hairs are alone of 
any value. ‘To have down at the base of the involucre is probably a 
frequent condition of S. oleraceus, not of S. asper. The form of the 
leaves is too inconstant to be of any value. ] 
4. Dr. Balfour described a specimen of Stifftia chrysantha, one of 
the arborescent Composite of South America, which had recently 
flowered in the Edinburgh Botanical Garden. Also a specimen of 
Quassia amara, which had shown flowering racemes. ‘The leaves 
of the latter presented remarkable transitions from a simple to a 
pinnate leaf, with a winged petiole. Notices of these will appear in 
the ‘ Edinburgh New Philosophical Journal.’ 
April 12.—Professor Balfour, President, in the Chair. - 
The following communications were read :— 
1. ‘ Alge Orientales ” (part 8), by Dr. Greville. In this com- 
munication Dr. Greville described Sargassum gracile, S. leptophyllum, 
and S. flexile. ‘This paper will appear in the ‘ Annals of Natural 
History ’ and in the Society’s Transactions. 
2. “On the Irritability of the Style of various species of Gold- 
fussia,” by J. S. Sanderson, Esq. In this paper Mr. Sanderson 
entered into a detailed statement of the structure of the style of 
Goldfussia, and endeavoured to show that the explanation given by 
Morren of the cause of the movements is not satisfactory. 
The style of Goldfussia curves outwards, the stigmatic papille 
occupying the convexity of the curve. The irritability resides in 
the papille. ‘The change produced by irritation consists—lIst, in 
the disappearance of the curve, the style being brought into the 
straight position ; 2nd, in its being curved in the opposite direction 
to a greater or less extent. In the moving part of the organ, or 
that corresponding to the stigmatic surface, the arrangement of the 
parts is the same as in Mimulus. An elastic epidermis covers the 
surface opposite to that occupied by the stigmatic papille. The 
vessels and cylindrenchymatous tissue are interposed, the former 
being in apposition to the epidermis, the latter occupying the re- 
mainder of the space. Spiral vessels contribute to the elasticity of 
the stigma. 
The cylindrenchyma appears to be the tissue in which the changes 
are produced, giving rise to the irritability. The true stigma of 
Goldfussia, like that of Mimulus, consists of a surface presenting 
conical papillz, in connexion with which are the cylindriform cells, 
which are continuous with those forming the general conducting 
tissue of the style. In Mimulus and in Goldfussia anisophylla each 
cylindriform cell terminates in a papilla. Hence Morren deduces an 
explanation which he considers tenable, and which he gives as the 
conclusion to be drawn from his researches. He supposes that the 
motion of the style depends on a sudden transference of the granules 
which are lodged in the papille to the opposite extremities of the 
cylindrical cells. “This phenomenon he believes to be dependent on 
