parr] © THE MECHANISMS OF FLOWERS. 393 
_ protects it from short-lipped insects: it is all the more diligently 
sought therefore by insects whose proboscis is sufficiently long. 
i An insect in inserting its proboscis brings it in contact first with 
_ the anthers, which stand in the mouth of the tube, and then with 
_ the stigma, which is lower down: stigma and anthers are matured 
simultaneously. If a smooth, dry needle be thrust into the flower, 
it may readily be seen that as it enters no pollen sticks to it, and 
as it is withdrawn pollen only adheres to it for 2 to 4 mm. at the 
end, where it is moist with honey. The same thing doubtless 
takes place in the case of honey-sucking insects, which must 
therefore perform cross-fertilisation regularly ; while pollen-feeding 
insects can scarcely ever effect cross-fertilisation, but must often 
‘cause the loosened pollen to fall upon the stigma and lead to self- 
fertilisation. In absence of insects, self-fertilisation always occurs 
ultimately. 
_ According to Batalin (38), there are two cultivated varieties— 
one proterandrous, the other proterogynous. I have only once 
‘seen the proterandrous variety ; all the plants on which I made my 
_ observations were homogamic. 
_ Sprengel never observed insects on this plant. 
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~ TO TER 0, i TAS ome 
Visitors : A. Hymenoptera—(a) Apide: (1) Bombus lapidarius, L. § 9 
 (10—14), ab. ; (2) B. terrestris, L. § 2? (7—9); (3) B. hortorum, L.? § 
 (18—21), very ab. ; (4) Apis mellifica, L. $ (6), ab. ; all sucking. (To judge 
from the length of its proboscis, the honey-bee can obtain only part of the 
honey) ; (5) Eucera longicornis, L. ¢ (10—12) ; (6) Anthophora pilipes, F. 
~ 2 ¢ (19-21), ab. ; (7) Osmia rufa, L. 9 (7—9), ab., the three last sucking ; 
(8) Halictus albipes, F. 9 ; (b)Vespide: (9) Odynerus sp. ; the two last seek 
in vain for honey. B. Diptera—(a) Bombylidw: (10) Bombylius major, L. 
(10), s. ; (6) Syrphide : (11) Rhingia rostrata, L. (11—12), very ab., s. and fp. ; 
(12) Xylota segnis, L., f.p., after seeking in vain for honey; (13) Syritta 
" pipiens, L. (3), f.p. ; (14) Eristalis sepulcralis, L., fp. ; (15) E. arbustorum, L. 
_ (4-5), f.p. ©. Lepidoptera—(a) Rhopalocera : (16) Papilio Machaon, L. (18) ; 
(17) P. Podalirius, L.; both ab. (Stromberg) ; (18) Vanessa urticz, L. (12), ab. ; 
(19) Pieris cardamines, L. (11) ; (20) P. brassicae, L. (15) ; (21) P. napi, L. ; 
7 (22) P. rape, L.; all three ab. ; (b) Sphinges: (23) Macroglossa fuciformis, L., 
_ freq. (Stromberg) ; (24) M. stellatarum, L., do. 
i 
Syringa persica, L., is gynomoncecious (605). _ 
+e 
292, LIGUSTRUM VULGARE, L.—Honey is secreted by the ovary, 
and lies at the base of the tube, which is scarcely 3 mm. long 
and expands above into a four-lobed, rarely five-lobed, limb. The 
- more or less distinctly bilobed stigma is situated at the mouth of 
the tube, The two (rarely three) stamens are matured simul- 
wae 
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