PART III. | THE MECHANISMS OF FLOWERS. 345 
_ Although in the first stage this cylinder, coated above with pollen, 
and in the second the tip of the style, with its two rows of stigmatic 
} - papille, projects 5 to 7 mm. above the segments of the corolla, 
many florets are fertilised simultancously by the bees which 
a visit the flowers, particularly by those with abdominal collecting 
i brushes, which diligently sweep up the pollen upon the surface af 
the capitulum. 
Hl On the southern slopes of Miihlberg and Wandersleber 
_ Schlossberg in Thuringia, where I observed Onopordum, the two 
_ handsomest thistles, Onopordwin Acanthium and Cirsium ertophorum, 
_ were fertilised chiefly by the handsomest of the tailor-bees, Megachile 
| lagopoda, K. ‘The females fly boisterously on to a thistle-head 
and brush hurriedly over it, holding the abdomen sometimes so 
high that one can see from far off the red, hairy coat of its under 
_ side, or the blue pollen adhering to it. The mid and hindlegs 
are actively occupied meanwhile in a backward scratching move- 
ment, and the head is sunk among the florets. As a rule the 
female turns once round upon the capitulum in brushing off its 
pollen. On leaving one capitulum it flies at once to another, © 
until, being laden with sufficient pollen, it flies off to its nest. 
‘The males also sit occasionally sucking honey upon these thistle- 
heads, but they are much more occupied in pursuing the females. 
Delpino’s generalisation, based on insufficient observations, that 
_ Composite whose florets are packed closely together to form a level 
surface are fertilised by bees with abdominal collecting-brushes, 
‘while those whose essential organs are long and widely separate 
are fertilised by Halictus, is shown to be incorrect by this and by 
many more of my observations. 
i. Visitors (in Thuringia): A. Hymenoptera—(a) Apidae: (1) Megachile 
 lagopoda, K. ? ¢, cp. and s., in extreme abundance ; (2) Osmia fulviventris, 
| Pz. 9 f, cp. ands. ; (3) O. spinulosa, K. 9, ep.: (4) Coelioxys conoidea, Ill. 
 9,s.; (5) Stelis aterrima, Pz. 9 3,s.; (6) Andrena Schrankella, N. 9; (7) 
_ Halictus quadristrigatus, Latr. 2, s. ; (8) Saropoda bimaculata, Pz. 2, s. ; (9) 
oe lapidarius, L., $,s. ; (10) B. terrestris, L. 9, s.; (11) B. rupestris, 
om 9,8. ; (0) Sphagidin : (12) Psammophila affinis, K. 9,s. B. Lepidoptera 
| (a) Rhopalocera : (13) Vanessa urtice, L., s.; (14) Satyrus Galathea, L., s. ; 
_ (b) Sphinges : (15) Macroglossa stellatarum, e s. C, Coleoptera—(16) Cocci- 
- nella mutabilis, Scriba, trying vainly to reach the honey. D. Hemiptera— 
(17) Capsus, two species, s. See also No. 590, 11., and No. 609. 
_ 256. SERRATULA TINCTORIA, Lae 
_. Visitors (at Mithlberg in Thuringia, Sept. 1871): A. Hymenoptera— 
. - Apide : (1) Bombus agrorum, F. ? ¢,s.,ab. B. Lepidoptera— Rhopalocera : 
(2) Colias hyale, L., s., ab. 
