104 THE FERTILISATION OF FLOWERS. [PART III. 
making for the smaller honey-glands. With reference to the 
likelihood of cross-fertilisation the same remarks hold good as in 
the case of Nasturtiwm silvestre. In many flowers the shorter 
anthers stand lower than the stigma, in others on a level with it 
or even higher. In the two last cases they may aid in self- 
fertilisation. 
Cardamine pratensis surpasses all the other Crucifers which grow 
wild near Lippstadt in the conspicuousness of its flowers and the 
abundance of its honey, and consequently in the number of its 
insect visitors. 
A. Hymenoptera—A pide : (1) Halictus cylindricus, F. 2. ¢p.; (2) An- 
drena dorsata, K. 9,s.; (3) A.parvula, K. 9 ¢, cp. ands. ; (4) A. Gwynana, 
K. 2, ¢p., (once it flew straight from the Curdamine to a short-styled flower 
of Primula elatior and gathered pollen there also) ; (5) Nomada lateralis, 
Pz. 9,s.; (6) N. lineola, Pz. ¢,s.; (7) Osmia rufa, L. ¢,s.; (8) Bombus terrestris, 
L.?,8.; (9) Apis mellifica, L. $, very ab., c.p. ands. B. Diptera—(a) Bom- 
bylide: (10) Bombylius major, L., once, hovering over the flower and suck- 
ing,—it passed straight from the Cardamine to Primula elatior; (11) B. 
discolor, Mgn., s. ; (6) Empide : (12) Empis opaca, F., s. ; (c) Syrphide : (13) 
Rhingia rostrata, L., f.p. ; (14) Helophilus pendulus, L., s. ; (d) Muscide : (15) 
Anthomyia sp., fp. ©. Lepidoptera—(16) Rhodocera rhamni, L. ; (17) Pieris 
brassicee, L. ; (18) P. napi, L. ; (19) Anthocharis cardamines, L. D. Coleop- 
tera—(a) Nitidulide: (20) Meligethes, ab., lh.; (6) Staphylinide: (21) 
Omalium florale, Pk., very ab. E. Thysanoptera—(22) Thrips, s. and fp. 
See also 590, I. 
Cardamine chenopodifolia, Pers., has cleistogamic flowers which 
burrow into the earth (296). 
Cardamine impatiens, L., is visited by Andrena albicans, 
K. 9 (590, 1.). | 
Barbarea vulgaris, R. Br—EKach of the two shorter stamens has 
on either side of its base a small, green, fleshy honey-gland ; a some- 
what larger honey-gland is placed between each pair of longer 
stamens, externally to their bases, in the position of the two short 
stamens that have disappeared. On each of the six glands a colour- 
less drop of fluid may be seen in fine weather. The anthers are 
placed as if the glands between the longer stamens were absent. 
The taller stamens, which overtop the stigma, make a quarter of a 
revolution towards the neighbouring short stamens ; this movement 
begins with the dehiscence of the anthers immediately after the flower 
expands, and is just finished when the anther is completely covered 
on one side with pollen. The two shorter anthers, which are on a 
level with the stigma, remain turned towards it even after dehis- 
cence, so that the position of the anthers is the same as in 
