parrut] THE MECHANISMS OF FLOWERS. 373 
Rhopalocera : (90) Polyommatus Phleas, L., s., ab.; (91) P. Dorilis, Hfn., freq. ; 
92) Lyceena egon, W. V. ¢ ; (93) Satyrus Janira, L., ab. ; (94) S. pamphilus, L.; 
5) Hesperia thaumas, Hfn. ; (b) Sphingidee : (90) Tn statices, L.- D. Solas 
optera—(a) (demeride : (97) CEdemera virescens, L. ; (b) Cerambycide : (98) 
eptura livida, L., freq., lh. ; (c) Chrysomelide : (99) Cryptocephalus sericeus, 
A list of ingtéeti additional visitors is given in No. 590, III. 
a 
¢ 
F 
7 Jasione montana stands in the front rank of our native plants 
in regard to the number and variety of its insect-visitors ; it is only 
ig x atched by some Umbelliferee and Compositz, which es with it 
the advantages of fully-exposed honey, and the union of numerous 
. owers with freely-projecting reproductive stigmas and anthersin a 
‘conspicuous inflorescence. In all such plants, cross-fertilisation is 
completely insured, and accordingly the possibility of self-fertilisa- 
tion has been lost. 
Orv, VACCINIACE ZL. 
284, Vaccinium Myrrtiuvus, L.; 285, V. uLiainosum, L.— Both 
species are slightly proterandrous, and resemble Hrica tetralix in 
their mode of fertilisation. 
_ In PV. Myrtilius, according to Sprengel, honey is secreted and 
borne by the white annular ridge or disk which rests upon the 
ovary and surrounds the style ; I have never found this disk moist, 
even when the wide part of the corolla is quite wet with honey ; 
it is moreover not so smooth as honey-glands usually are. On the 
other hand, I have very frequently found in both species a drop of 
| per at the outer side of the base of each stamen; and as the 
base of the corolla immediately above its insertion is all round 
} Bach thicker and fleshier than the upper portion, I at first did not 
4 d oubt that it secreted the honey. But I have since convinced 
nyself that Sprengel was right, and that the drops of honey secreted 
by the epigynous disk pass between the filaments to the wall of 
the corolla. 
So far, both species agree with one another : but in other respects 
each has certain advantages over the other. V. Myrtillus secretes 
_ More honey, which is lodged in a much more globular corolla; the 
opening is narrowed so that only insects with a proboscis long 
enough to reach from the exterior to the base of the corolla can 
obtain the honey. On the other hand, V. uliginoswm forms taller 
bushes bearing much more numerous flowers, which are red on 
| the side turned towards the light and therefore much more con- 
- Spicuous while the mouth of the corolla is 3 mm. wide, permitting 
