PART III. | THE MECHANISMS OF FLOWERS. 445 
dull weather while the flower is still fresh; in the fifth it occurs in 
many flowers, and in the sixth in all, at the very outset. The 
honey is secreted and guarded in much the same manner in all six 
species, and so the likelihood of insect-visits can only depend upon 
the conspicuousness of the flowers. 
Wulfenia carinthiaca, Jacq., is proterogynous (Hildebrand, 
No. 351). 
Bartsia alpina, L., is proterogynous, and is fertilised by humble- 
bees. The stigma and anthers have the same relative positions as in 
Rhinanthus mayor (Fig. 156). Self-fertilisation is impossible (609). 
330. ODONTITES SEROTINA, Rchb. (0. rubra, Pers., Huphrasia 
Odontites, L.).—Honey is secreted by the lower parts of the ovary, 
which is smooth, and swollen anteriorly (4, 6), while the upper part 
Fig. 152.—Odontites serotina, Rchb. 
1.—Bud, with exserted stigma (x 34). 
2.—Flower, with the stigma lying between the anthers.@ 
3.—Flower, whose style projects far beyond the anthers. 
4.—Flower, in which the style lies to one side. 
5. 
“ae two stamens of the left half of the flower, seen from the inside (x 7). 
6.—Ovary. 
a, base of the corolla; b, nectary; ¢, upper hairy part of the ovary; d, style; e, hairs which 
unite the anthers ; f, hairs which prevent pollen from being scattered at the sides; g, sharp teeth 
which prevent the bee from thrusting its proboscis between the bases of the filaments; h, path 
taken by the bee’s proboscis. 
(The flowers 2 and 4 should slant more forwards than they are here figured.) 
is hairy : it is lodged in the base of the corolla, whose tube is 4 to 
5 mm. long, and smooth within; the broad stamens, which almost 
block the entrance of the tube, guard it from rain, and two to four 
purple spots at the base of the lower lip serve as guides towards it. 
The stamens almost touch each other below, where they are 
covered on their inner sides with sharp points; close under the 
anthers they are smooth and lie more widely apart. <A bee, after 
alighting on the three-lobed under-lip, which affords a convenient 
landing-place, can only thrust its proboscis into the flower close 
