Page:Popular Science Monthly Volume 27.djvu/622

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THE POPULAR SCIENCE MONTHLY.

surface of which is mostly well provided with oblique rows of long bristles. The maxillæ (K) and part of the labial palpi (T) are modified into flat, leaf-like, linear processes, which are arranged around the tongue (R), and thus complete the suctorial proboscis. While, therefore, the suctorial apparatus of the butterfly consists simply of a coiling or suctorial tongue, it must be noted that in the bee other parts are concerned in the formation of the tubular sucking apparatus. In many bees, besides, the tip of the tongue is peculiarly modified, so as to enable the insect to taste the honey before beginning to collect it, an arrangement by which honey of unpleasant taste can be rejected.

Apparatus foe collecting Pollen.—Of all insects the bees alone have certain parts of their body specialized for the collection of pollen. The structures developed for this end are in their way perfect. They may be found either on the ventral surface of the posterior portion of the body or on the legs. Accordingly, bees may thus be divided into two groups: 1. Bees having structures for the collection of pollen on the ventral surface of the body; and, 2. Bees having such structures on their legs. To the first group belong the mason-bees (Osmia) and the leaf-cutter bees (Megachile). In these species the ventral surface of the abdomen is furnished with long, stiff, retroverted hairs, by means of which the pollen is brushed from the anthers as the insect passes in or out of the flower. The grains get entangled among the hairs, from among which the bee afterward dislodges them by means of its legs.

This contrivance is admirably adapted for obtaining pollen from flowers having a flat corolla, but not for such as have the anthers concealed in a deep tube. Our most highly developed bees (humble-bees, honey-bees, etc.) have therefore apparatus suitable for collecting pollen from flowers of all shapes.

The most highly developed bees collect the pollen on the hind-legs, but all do not possess the structures adapted to this purpose in like perfection. Fig. 17 represents one of the hind-legs of the hairy-bee (Anthophora retusa, compare Fig. 13); we here see the trochanter (R), the femur (S), the tibia (T), the tarsus (P), the four other joints of the foot (F), and, finally, the two claws (K). The tarsus (P) and the tibia (T) bear the structures by which the pollen is collected; both are seen to be laden with many grains of pollen (left white in the illustration). The tibia and tarsus are broad and flat, and are thickly covered with hairs. The pollen is brushed from the anthers by means of the hairs on the tarsus (P), and is afterward transferred to those of the tibia (T), where they are suffered to remain until the hive is reached. In the humble-bee (Fig. 18, Bombus terrestris) the same arrangements are carried out in yet greater perfection. The tibia (T) is smooth on the outer surface, while the inner surface is covered with long, stiff hairs, which form with the surface of the tibia a little depression, into which the pollen is brushed by the short hairs of the tarsus. In the honey--