2o6 A NGIOSPERMAE— DICOTYLEDON ES 



a continuation of the tube, slightly wider and open in front, and an under lip, whose 

 base (3 to 5 mm. long) is applied to the upper lip so as to close up the lower 

 3 to 5 mm. of the mouth of the flower. The hooded end of the upper lip encloses the 

 stamens, and the end of the style with the stigma protrudes obliquely downwards 

 from it ; the free portion of the under lip with its three lobes serves as a standing- 

 place for insects, and is set very obliquely, so that the right lobe stands 2 to 8 mm. 

 higher than the left (i, Fig. 304). If the under lip is pulled down as far as the place 

 of its attachment, the mouth of the flower is seen to form a fissure 8 to 10 mm. long, 

 which in the greater part of its length is only i to 2 mm. broad, but which 3 mm. 

 below its upper end widens out suddenly to a breadth of 4 mm. (e, e, i) ; it then 

 again narrows suddenly, and a litde more than i mm. from its upper end two sharp 

 processes of the hood {g, i, 2) almost meet in the middle and divide the entrance 

 into a very small upper and a long lower part. Through the upper opening pro- 

 trudes the style, which springing from the bilocular ovary lies close to the posterior 

 wall of the corolla, and curves sharply downwards near its anterior end to bear the 

 capitate stigma ; the long, lower opening admits the bee's head. So long as this 

 slit is only i to 2 mm. broad, viz. from the insertion of the under lip to the wider 

 part above, its edges are very markedly rolled outwards, and that part of the inner 

 wall of the corolla which is brought by this revolution of the edge to form the 

 margin of the narrow slit is closely set with sharp points {d, i, 2, 4), while the 

 wider portion {e, i) has smooth edges. There is also on each side of the upper lip 

 a reddish thickened band (h, 2), which begins on a level with the wide part of the 

 slit at the upper end of the reflexed edges («), and forming a sharp angle with 

 the ridge runs backwards and downwards to disappear on a level with the base of 

 the under lip. 



' What have all these characters, the compressed base of the under lip, the 

 oblique position of its three-lobed lamina, the reflexed edge of the narrow entrance, 

 its rough edges, the sudden enlargement with its smooth edges, the red stripes at the 

 sides of the upper lip, to do with fertilization by humble-bees ? Are they accidents 

 to be neglected, as is done by Hildebrand in his figures in the Boianische Zeitung, 

 and by Dr. Ogle in the Popular Science Review ? Careful observation of an insect 

 visiting the flower makes me think otherwise. The bee comes flying along with 

 outstretched proboscis, and avoiding the toothed edges of the slit, thrusts its proboscis 

 at once in alighting into the widest part of the opening {e, r ) ; the upper part of its 

 head then touches the stigma, which stands scarcely 2 mm. above the wide part of 

 the opening, and the oblique position of the lower lip causes the bee's head also to 

 be placed obliquely ; its forefeet grasp the basal part of the lower lip, its middle pair 

 of feet grasp the tube of the flower on a level with the lower lip, and the hindfeet 

 I'est upon leaves or other flowers below. Standing in this position, the bee applies 

 its head, which is 2\ to 3 mm. thick and 5 mm. broad, to the (4 mm.) wide part of 

 the entrance, with just so much obliquity as gives it the best chance of entering. 

 And now the edges of the slit, rolled outwards and thereby stiffened {d, i, 2), and 

 the bands on the upper lip {h, 2), play their part. Joining above at a sharp angle, 

 they bound, on each side of the upper lip, a triangular surface, which does not bend, 

 but gets pushed outwards by the bee's head. But the points where the reflexed edges 

 and the thickened bands meet are on each side of the wide point of the opening. 



