q PART III. | THE MECHANISMS OF FLOWERS. 109 
stigma and stamens with opposite sides of the proboscis, and, at 
least sometimes, by pollen-seeking forms. 
: Visitors : A. Diptera—(a) Stratiomyide : (1) Nemotelus pantherinus, L. 
 f.p.; (b) Syrphide : (2) Chrysogaster enea, Mgn. (Tekl. B.), f.p. ; (3) Eris- 
talis nemorum, L.; (4) E. tenax, L., both f.p.; (5) Volucella pellucens, L. 
(Tekl. B.); (6) Rhingia rostrata, s., very ab. B. Hymenoptera—A pide : (7) 
 Halictus leucopus, K. 2 ; (8) Andrena albicans, K. ?; (9) Apis mellifica, L. 
 %,allthree cp. C. Lepidoptera—{10) Pieris brassice, L., s.; (11) P. napi, 
Ls. ; (12) P. rape, L., s. D. Coleoptera—(13) Anthocomus fasciatus, L. See 
also, 590, II. 
35. ALLIARIA OFFICINALIS, Andrzj. (Sisymbrium Alliaria, 
_ Scop).—The honey-glands agree in character and situation with 
those of Cardamine pratensis. But while in C. pratensis the honey 
- is secreted towards the outside, and collects in the pouched sepals, 
in A: officinalis it exudes inwards from the glands at the base of 
the short stamens, and forms four drops in the base of the flower. 
These each lie between a short stamen and the adjacent’ long 
one, and finally fill the lower part of the space between the 
stamens and pistil, to which parts they adhere firmly. I have 
never observed secretion on the part of those glands which occupy 
_ the position of the two aborted short stamens; they seem to be 
 functionless ancestral structures. The sepals, which persist as 
receptacles for the honey in C. pratensis, are in A. officinalis only 
useful in the bud, as a protection for the parts within, and by 
~ contributing by their white colour to the conspicuousness of the 
inflorescence ; when the flower expands they cease to be of use 
and easily disp off. 
: All the anthers dehisce inwards; the inner ones surround the 
_ stigma so closely that they alnaye effect self-fertilisation, and 
_ this, as I have proved, leads to the production of good seed. 
_ Cross-fertilisation must, as in the foregoing species, be effected 
i very frequently by honey-seeking insects, and at times by pollen-- 
__ seeking species ; and it probably then outstrips self-fertilisation in 
its action. 
Visitors: A. Hymenoptera—Apide : (1) Apis mellifica, L. $,s. B. Dip- 
tera—(a) Syrphide: (2) Syrphus decorus, Mgn. (Tekl. B.); (3) Rhingia 
rostrata, L.,s.; (b) Muscide : (4) Anthomyia, s. C. Coleoptera—(a) Nitidulide : 
_ (5) Meligethes, ab.; (6) Epurea; (b) Curculionide: (7) Ceutorhynchus, a 
minute species. See also 590, Il. 
36. SISYMBRIUM OFFICINALE, Scop.—The structure of the 
flower agrees fairly with that of the foregoing species. Each of 
