176 MR. T. Н. CORRY ON ASCLEPIAS CORNUTI. 
lumen, so that no trace of it whatever remains which can be detected on section. 
Schleiden (loc. cit. p. 380, note), however, states that in S¢apelia two point-like ехсата- 
tions are frequently seen on the upper surface of the style-table, which are traces of this 
confluent “canal.” Sprengel (Гос. cif.) observed a somewhat similar appearance in 
Gomphocarpus fruticosus, R. Br. (Asclepias fruticosa, L.); for he describes the existence 
of a slight slit in the centre of the upper surface of the style-table in that species, and he 
found, on passing a knife down it, that it ended inferiorly between the lower parts of the 
two styles and the two ovaries. Jacquin (*Genitalia, pl. 2. fig. 2) also figures in 
Asclepias curassavica, L., a central median line in the apex of the style-table, which is 
evidently only another trace of the formerly existent “canal.” Each anther occupies а 
position corresponding to one of the flat or, rather, concave surfaces of the pentagonal style- 
table. The lateral marginal borders of the anther, which are beyond the anther-cells and 
touch the angles of the style-table, become thin, membranous, and hyaline, forming broad, 
rigid, cartilaginous flaps, which are often bent sharply outwards and backwards so as to 
project strongly, nearly at a right angle, from the rest of the anther, and at fully a right 
angle from the column formed by the staminal filaments. In shape each flap is more or 
less triangular, narrowing to a point above, while its base is acute; and here it turns 
slightly upwards, so that the broadest portion is just a little above the base. These flaps 
have been called the “anther wings," ог“ anther ale," and are believed by some botanists 
to be expansions of the base of the connective or else of the filament to which the anther 
is affixed. In my opinion they are expansions of the sides of the connective. 
I will now give, as briefly as possible, the results I have arrived at with regard to the 
mode of development of the corpuscula and their appendages. 
Immediately before the period of union between the stamens and the style-table a 
shallow longitudinal furrow, at first extremely faint, may be observed along the middle 
of each of the five prominent angles of the style-table. This groove is somewhat wide at 
its lower end, but narrows slightly towards the apex of the table, and dies away abruptly 
where the top of the pentagonal mass forms a rounded projecting eave. These five 
grooves, therefore, alternate with the anthers and nectaries (which latter have not yet 
appeared), and are opposite the corolla lobes. The sides and floor of each of them are 
lined by the moderately thick uncuticularized columnar epidermis which covers the surface 
of the style-table; but in the region of the groove the cells are elongated perpendicular to 
the surface, and slightly rounded at their free ends. The epidermis, therefore, in this 
region has a remarkably sharp and distinct definition. The upper portion of the groove 
soon becomes both deeper and wider for a short distance; and this is owing to the cells 
which line it and form its sides becoming, for a comparatively limited area, very long, 
thin, and papilliform, with rounded projecting ends, 
presenting a villous appearance in 
surface view. | 
These papilliform cells are actively excretory, and they exude a gummy adhesive matter, 
which occupies the intervals between the projecting ends of the papilliform cell, which, as 
it dries, forms a sheet and becomes hardened externally. So great, however, is the amount 
of successive additional secretions that the gum speedily covers even their free ends, form- 
ing a flat membrane, into the lower part of which the cells fit, while the portions which 
