———s 
PART III. | THE MECHANISMS OF FLOWERS. 499 
Cross-fertilisation is favoured by the feebly-marked proteran- 
drous dichogamy, and by the relative positions of stigma and 
anthers. At first, the divisions of the style lie close together 
behind the anthers (1, Fig. 168) ; afterwards, when the pollen is 
removed, they diverge more and bend down in front of and below 
the anthers (2, Fig. 168). In sunny weather bees’ visits are so 
plentiful that all the pollen is removed before the stigmas diverge 
and bend downwards. During rainy weather, and in plants kept 
in the house, great part of the pollen as it escapes from the anthers 
remains adhering to the long woolly hairs which cover the under 
surface of the upper lip, and the inferior stigma curving down- 
wards among these hairs becomes covered with the pollen of its 
own flower. 
Visitors: A. Hymenoptera—Apide: (1) Apis mellifica, L. $,s. (6) ; (2) 
Bombus Rajellus, Ill. 9 (12—13), s. ande.p. ; (3) B. silvarum, L. (10—12), s. ; 
(4) B. lapidarius, L. § (10—12), s.; (5) B. hypnorum, L. § (10—11), s.; (6) 
B. muscorum, F. 9 (13—14), s. ; (7) B. (Apathus) rupestris, F. 9 (11—14), 
s.; (8) Anthophora quadrimaculata, Pz. 9 ¢ (9—10), s. and ¢.p., very ab. ; 
(9) A. furcata, Pz. 9 g, 8. ande.p., scarcer (Thur.) ; (10) Osmia aurulenta, Pz. 
Q (8—9),s. (Thur., Sld.) ; (11) O. enea, L. 2 (9—10),s. ; (12) O. fulviventris, 
Pz. 9, s. (Thur.); (13) Anthidium manicatum, L. 9 ¢, wherever Ballota 
grows, very ab, in sunny weather, the females diligently collect pollen and 
suck honey, while the males buzz about and occasionally descend to suck honey 
on a flower ; (14) Megachile pyrina, Lep. (fasciata, Sm.) 2, s. B. Lepidoptera 
—(a) Rhopalocera: (15) Argynnis Paphia, L.; (16) Vanessa urticee, L. (12) ; 
(17) V. cardui, L. ; (18) Pieris brassice, L. (15) ; (19) P. rapee, L. ; (20) Colias 
hyale, L. ; (b) Sphinges : (21) Macroglossa stellatarum, L. ; all these Lepidoptera 
were sucking ; the specimens I caught had their tongues dusted with pollen 
and were probably effecting fertilisation. See also No. 590, m1. 
In Prostanthera, Labill., long two- or three-toothed appendages 
of the connectives come in contact with the insect and cause 
shedding of the pollen (178, 360). 
365. TEucRIUM ScoroponiA, L., is markedly proterandrous.! 
_ When the flower opens, the stamens protrude from it, lying close 
_ to the superior wall of the tube, and continuing in a line with it, 
or bending slightly forwards. The two divisions of the style are 
already separate but stand behind the stamens so that they escape 
_ being touched by the head of a bee visiting the flower; the 
anthers, which dehisce inferiorly by a longitudinal slit, shed their 
1 The proterandry of Teweriwm and the movements of its reproductive organs 
' ~ aebe ay described’ by Delpino, No. 178, Hildebrand, No. 360, pl. x., and Ogle, 
No. 632. 
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