374 THE FERTILISATION OF FLOWERS. [parr nr 
the smaller insects to insert their heads or the whole forepart o 
the body. V. Myrtillus has thus adapted itself exclusively for the 
long-proboscised bees (hive-bees, humble-bees), which are con: 
spicuous for their skill and diligence; they know that within 
the inconspicuous corolla they will find a rich store of honey, and 
seek it so assiduously that hundreds of the flowers are visited anc 
fertilised by a single insect. V. uliginosum has adapted itself by 
its more conspicuous flowers and more accessible honey to much 
more various insects; it is much less frequently and less 
assiduously visited by the long-tongued bees than V. Myrtillus, 
for the greater part of the honey is carried away by the short: 
lipped insects. 
Fig, 121. 
1.—Flower of Vacciniwm Myrtillus, slightiy magnified, from the side. 
2,—Flower of V. wliginoswm, after removal of half the corolla (x 7). 
The difference in size of the mouths of the corolla causes als 
another difference, illustrated in Fig. 121. In V. Myrtillus th 
stigma projects a little beyond the corolla, and, as every insec 
visitor inserts only its proboscis into the flower, the stigma is certail 
to be touched by the insect’s head before the latter receives th 
pollen shed upon it. In V. uliginoswm, if the stigma occupied th 
same position, the smaller bees (Halictus and small Andrene 
Nomad) might enter the flower without ever touching the stigma 
whereas, placed as it is, immediately within the entrance, it must 
be touched by even the smallest insects entering the flower. If 
have verified by direct observation this marked distinction between 
the insect-visitors of the two species, | | 
