PART III. | THE MECHANISMS OF FLOWERS. 411 
(1) Apis mellifica, L. $, very ab., s. and c.p.; (2) Bombus pratorum, L. ?, 
s. and c.p. ; (3) Halictus zonulus, Sm. ?, s.; (4) H. sexnotatus, K. 9, s., ab. ; 
(5) Megachile centuncularis, L. ¢,s. See also No. 590, 111. 
302. ANCHUSA OFFICINALIS, L. (Sprengel, Pl. 111., 10,11, 16,17). 
—Honey is secreted by the green fleshy base of the ovary and 
accumulates in the lower part of the corolla, which forms a tube 
7 mm. long. The corolla is smooth within, but its entrance is 
guarded from rain and from unbidden guests (flies) by five closely 
approximated, hairy, invaginated processes. At its upper end the 
tube expands into a limb 10 mm. in diameter, at first concave and 
violet in colour, then flat and deep-blue; and further, the flowers, 
which are conspicuous in themselves, are rendered more so by 
aggregation, The invaginated appendages, which are indicated 
on the outside of the corolla by transverse slits, serve by their 
white colour as honey-guides. The anthers, which dehisce in- 
trorsely, and the stigma which overtops them, are matured simul- 
taneously. Cross-fertilisation is insured, in case of insect-visits, by 
the position of the stigma; in absence of insects, self-fertilisation 
must finally occur, for the corolla in falling off brings the anthers 
in contact with the stigma. 
Eug. Warming has found A. officinalis heterostyled, with 
transition-forms between the long- and short-styled flowers (762). 
Insect-visits are plentiful, and in fine weather cross-fertilisation 
always occurs. On September 13, 1871, I observed the following 
insects visiting this plant on the Wandersleber Schlossberg in 
Thuringia :— 
A. Hymenoptera—A pide : (1) Apis mellifica, L. $,s. and c.p., ab.; (2) 
Bombus pratorum, L. §, 8. and c.p. ; (3) B. agrorum, F. ¢ 9 ; (4) B. silvarum, 
L. ¢; (5) B. lapidarius, L. ¢ §; (6) B. muscorum, F. § ; the last four only 
sucking. B. Lepidoptera—Nociue: (7) Plusia gamma, L., very ab., s. See 
also No. 590, 111., and No. 609. 
303. Lycopsis ARVENSIS, L.—The same parts of the flower as 
in Anchusa serve to secrete, contain, shelter, and point out the 
honey. The flowers are doubtless visited and fertilised in like 
manner, chiefly by bees, and to some extent also by Lepidoptera. 
I have only observed (September 8, 1871, in Thuringia) Hesperia 
thaumas, Hufn., once sucking honey on this plant. 
Pulmonaria angustifolia, L. (P. azwrea, Besser).1—This plant is 
dimorphic ; and the two forms of flowers, besides differences in the 
reproductive organs, show an unusual number of other minor 
1 Darwin (No. 167) has taken P. angustifolia, L., and P. azurea, Besser, to be 
distinct species. 
