CAMPANULACEAE 



27 



elongates to some 12 mm., and when all the pollen adhering to it has been removed 

 the whitish stigma expands. Automatic self-pollination is therefore excluded. 



Visitors. — Kirchner observed butterflies (Vanessa urticae Z., and Epinephele 

 janira L.). MacLeod (Pyrenees) noticed a bee, a Lepidopterid, 2 flies, and a beetle. 



LIX. ORDER VACCINIACEAE LINDL. 

 518. Vaccinium L. 



Feebly protandrous bee flowers, or flowers with concealed neclar, which 

 Sprengel says is secreted by a swelling on the ovary. There are appendages 

 to the anthers, projecting laterally or vertically, and when insect visitors strike 

 against these the pollen is shaken out. 



Hermann IMuUer (' Fertilisation,' p. 373) was at first inclined to doubt 

 Sprengel's view as to the position of the nectary, for he did not find the 

 swelling on the ovary moist with nectar. He suggested that the swollen bases 

 of the filaments were secretory in function. The latter view was adopted by 

 Kerner ('Nat. Hist. PI.,' Eng. Ed. i, II). Later 

 on, however, Hermann Miiller admitted the 

 correctness of Sprengel's statement ('Alpen- 

 blumen,' p. 381), and Ricca has convinced him- 

 self that the swelling at the base of the style 

 really does secrete nectar (Atti Soc. ital. sc. nat., 

 Milano, xiv, 1871). 



Kerner says that in the species of Vaccinium 

 automatic self-pollination is ultimately possible, 

 for the flowers, though erect at first, become 

 pendulous, so that pollen can fall on the 

 stigma. 



1751. V. Myrtillus L. (Sprengel, ' Entd. 

 Geh.,' p. 230; Herm. Miiller, 'Fertilisation,' 

 PP- 373-5. ' Alpenblumen,' p. 381; Lindmann, 

 ' Bidrag till Kanned. om Fjellva.xt. Blomn. o. 

 Befrukt.' ; MacLeod, Bot. Jaarb. Dodonaea, 



Ghent, ii, 1891, p. 374, v, 1893, pp. 447-8; Loew, ' Blutenbiol. Floristik,' p. 395; 

 Knuth, 'Bloemenbiol. Bijdragen.') — This species bears feebly protandrous bee 

 flowers. These are bright-green in colour, with a reddish tinge, and odourless ; 

 but in spite of their inconspicuousness they are very rich in nectar. Sprengel says 

 that this is secreted by a white annular swelling on the ovary, surrounding the 

 base of the style. 



The pendulous corolla is strongly ventricose, and its mouth is so contracted 

 that only bees with a proboscis suflnciently long to reach the base of the flower 

 are able to act as pollinating agents. The capitate stigma projects a little from the 

 opening of the flower, and the head of an insect visitor therefore touches it before the 

 anthers, which are hidden within the bell. The latter lie above the stigma and 

 surround the style. They dehisce apically, and each of them possesses two long 



Fig. 215. Vaccinium, Z.. (after Herm. 

 Miiller). (i) Flower of V. Myrtillus Z,., 

 slightly etilarged and seen from the side. 

 (2) Do. of V. uliginosum L., seen from the 

 side after removal of half the corolla (x 7). 



