HYMENOPTERA BEES 163 



completely exposed nectar that have been passed over by the solitary long-tongued 

 bees are not despised by the social forms. 



The honey-bee occupies a special place among the species that are most 

 specialized with reference to flowers. As I was able to show in my work, ' Blumen 

 und Insekten auf den nordfriesischen Inseln' (pp. 174, 175), Apis at least in the 

 district referred to visits flowers of all classes and colours, though certainly giving 

 preference to bee flowers. My later statistical investigations showed that the hive- 

 bee also visits with special zest conspicuous social flowers, and flowers with nectar 

 completely or partly concealed (' Bliitenbesucher,' II, p. 10). 



Hermann Miiller obtained precisely similar results. In a hundred visits paid 

 by the honey-bee, he observed that the various classes of flowers received the 

 following numbers : 



In 



An and Po 72 



E 



EC 



C 



S 



H 



L 



It appears from these results that Apis prefers bee flowers, but also readily 

 visits social flowers and flowers with concealed nectar, as well as, in the lowlands, 

 flowers with half-concealed nectar. It follows, therefore, that the honey-bee occupies 

 an intermediate position between lorig-tongued and short-tongued bees as regards 

 its choice of flowers. The same thing is true of its colour predilections. 



Loew (' Blumenbesuch von Insekten,' I, pp. 6 et seq.) asserts that there is 

 a double reason why the honey-bee takes the foremost place among insects which 

 visit flowers, besides intelligence, in which it surpasses all its competitors. For 

 the work of pollination the constantly increasing community of the beehive surpasses 

 humble-bee societies and solitary bees, because it is able from the beginning of 

 spring till late autumn to send forth at any time a great number of individuals 

 well adapted to the requirements of flowers. No other bee can do this with the 

 same continuity. There are, in addition, physical advantages apart from the special 

 structure of the collecting and suctorial apparatus, by far the most important of 

 these being the medium length (6 mm.) of the proboscis. It is true that greater 

 elongation of this organ would render a number of humble-bee flowers accessible 

 to the honey-bee, from which it can now only obtain nectar by biting a hole, 

 but the possession of a longer proboscis would oblige it to give up visiting many 

 flowers with nectar entirely or almost entirely exposed, for these cannot be con- 

 veniently rifled by long-tongued visitors. Considering the honey-bee's particularly 

 large requirements in the matter of larval food, a proboscis of medium length would 

 appear to be the best conceivable equipment for enabling it to take precedence 

 of all competitors in regard to the number of flowers despoiled. 



Humble-bees also visit flowers of all classes, but greatly prefer humble-bee 

 flowers, bee flowers, lepidopterid flowers, and conspicuous social flowers; to a 



M 2 



