690 The Fertilization of Clitoria and Centrosema. [ November, 
In Centrosema the standard is either horizontal or considerably 
inclined, being nearly vertical in some cases; it is more nearly 
flat than in Clitoria, and its lateral margins are usually more or 
less noticeably bent downward. Near its base, on the middle 
Fic. 1—Flower of Clitoria mariana, with nearer half of vexillum removed, nat- 
ural siz 
Fic. Tone same with the nearer wing and= the nearer keel petal removed, as 
well as a part of the staminal tube and the nearer pe of the calyx 
Fic. 111.—Cross section (diagrammatic) of Fig. 1 
Fic. 1v.—Tip of the keel with the stamens a pe unnaturally protruded, 
d. 
Fic. v.—Flower of Centrosema virginiana seen from the side, natural size. The 
keel is bent so as to expose the anthers and stigma. 
Fic. vi.—The same from in front 
Fic. vit.—Vexillum of Fig. v1 in longitudinal pap natural siz 
Fic. vit1.—Keel after removal of the wings and standard, aie size, The 
dotted line pee the position of the stamen and pist 
In all figures æ indicates the anthers; c, the nee f the filaments; $, the 
guiding rela A, the collecting hairs; 4, the keel; #, the nectar-gland; , the 
_ point of union of keel and wings; 7, the nectar reservoir; s, the standard or vexil- 
lum; s¢, the stigma; x, part of the spring for retaining the keel in its normal posi- 
tion; v, the pouch for the stigma and anthers; zw, the wings; xy, the point at which 
: section, T, 11, is taken. 
