206 
MR. T. H. CORRY ON ASCLEPIAS CORNUTI. 
an alar fissure so that the corpusculum is cut vertically in half, and on the right side through 
a nectary slightly to one side of its middle. а.з. The lateral process of the anther united with 
the style-table. stig. The part of the stigmatic tissue which is exposed. 7. The radial groove 
on the apex of the column. 
Fig. 9. Nearly adult flower. Transverse section through the tissue of the staminal column a short 
distance above the origin of the nectaries, с, and below the point where the lower ends of the 
contiguous anther-ale arise and begin to diverge from it. For description vide p. 181 of the 
text. el. Ellipsoid space there referred to. 
Fig. 10. Transverse section through the tissue of the staminal column slightly above the preceding, 
and in the region where the lower ends of the anther-ale diverge from it. For description 
vide p. 181 of text. 
PuaTes XXV. & XXVI. 
Fig. 11. Transverse section in part of the region of the apex of the column, showing how the radial 
groove, 7, is formed by which the truly receptive surface, s/ig., on the base of the style-table is 
exposed to receive the pollen-tubes when the pollinium ruptures. Vide p. 182 of the text. 
The tapetal membrane, /ар., is represented as in its last phase previous to complete disap- 
pearance. The pollinia have fallen out of the anther-cells, an.lo. par. Parenchymatous tissue 
of the anther surrounding the anther-cells, which is subsequently absorbed when it dehisces. 
One of the styles (s/y.) is represented in transverse section near its upper termination in the 
style-table by which it is surrounded ; f.v.5., its fibro-vascular bundle; con. tis., the conducting- 
tissue on its inner side; æ., position of the “сапа! of the style.” 
е Fig. 12. Transverse section through Ше gynostegium in the region of the extreme apex of the styles. In 
the section next above this the conducting-tissue, con. tis., becomes continuous with that of 
the receptive surface. a.s. The lateral processes of the sides of the anthers forming the gynan- 
drous union in this region ; the bases of the anthers are free from the style-table. 
Fig. 13. The section passes in the median longitudinal line of an alar fissure. 0. Median part of the 
style-table, corresponding to the tissue internal to the fibro-vascular bundle in each of the two 
halves which fused to form it. с. External surface of style-table in contact on either side of 
the section with the anthers, and covered by a layer of epidermis. d. Parenchymatous tissue 
forming the bulk of the style-table. e. The receptive surface formed by the conducting-tissue, 
which is exposed by means of the open radial furrow, m. f. The upper part of a style. g. Its 
conducting-tissue. 1: The fibro-vascular bundle, continuous from the free portion of the style 
into the style-table. i. The upper end of the staminal column in the median longitudinal line 
of the alar fissure. Ж. The epidermis of the outer and inner surfaces continuous with each 
other. | 
Development and Structure of the Corpusculum. 
Fig. 14. Transverse section of a corpuscular furrow on one of the angles of the style-table, with the two 
Fig. 15. The same at a later stage. 
quadrant-shaped masses of gum excreted by the papilliform cells lining its sides; they have 
become partially solid. Тһе cells forming the floor of the groove have not yet bini to excrete. 
Vide p. 177 of text. 
The furrow has become deeper by the growing out of its sides, 
cell-division with growth occurring in the cells of its base. The two masses of gum of the pre- 
vious stage have been in consequence carried upwards to the mouth of the furrow attached to 
the cells which excreted them. In consequence of additional exudations from behind they have 
