506 



ANATOMY OF THE BEE. 



The alimentary canal ( Fig. 6) consists of a 

 tube extending through tlie entire body, and 

 coiled somewhat in the abdomen. The first 

 part above the mouth in the head is widened 

 to form the pharynx ( Phy) . Tlien follows 

 the long slender msophayus {(E), running 

 clear through the thorax and into the front 

 of the abdomen, where it enlarges into a 

 thin-walled bag, called, in general, the crop, 

 but which is known as the honey-stomach 

 ( HS) in the bee. Back of the honey-stomach 

 is a short na.YW\v proventicidus (P«;f?ii), which 

 is followed by the large U-shaped stomach, 

 or ventriculus ( Vent). Then comes the slen- 

 der smaZi intestine [SIy\i) with the circle of 

 Malpighian tubules {Mai) arising from its an- 

 terior end. Finally, forming the terminal 

 part of the alimentary canal, is the large 

 intestine, or rectum (iVeci), consisting of an 

 enormous sack, varying in size according to 

 its contents, but often occupying a large 

 part of the abdominal cavity. Six opaque 

 longitudinal bands on its anterior end are 

 known as the rectal glands {RQl) . 



The honey-stomach is of special interest 

 in the worker because the nectar gathered 

 from the flowers is held in it, instead of be- 

 ing sw^allowed on down into the stomach, 

 and is regurgitated into the cells of the 

 comb, or given up first to another bee in the 

 hive. The upper end of the proventriculus 

 sticks up into the lower end of the honey- 

 stomach as a small cone with an X-shaped 

 opening in its summit. This opening is 

 called the stomach-mouth. Its four lips are 

 very active, and take whatever food the 

 ventriculus requires from the honey-stom- 

 ach, for it must all go into the latter first, 

 while at the same time it affords the bees a 

 means of retaining nectar or honey in the 

 honey-stomach. 



The natural food of bees consists of pol- 

 len, nectar, and honey. The first contains 

 the nitrogen of their diet, and the other two 

 the hydrogen, carbon, and oxygen. Obser- 

 vations made by the writer indicate that 

 the pollen is not digested until it gets into 

 the intestine, for masses of fresh-looking 

 grains nearly always occur in the rear part 

 of the ventriculus, which is otherwise filled 

 with a brownish slime. On the other Imnd, 

 the nectar and honey is very probably di- 

 gested in the ventriculus, and in large part 

 absorbed from it. 



The salivary glands, located in the back 

 part of the head (Fig. 6, 8GI) and in the 

 front part of the thorax {301) open upon the 

 upper part of the labium (Fig. 3, F, SaWO) . 

 The saliva can thus affect the liquid food 



before the latter enters the mouth, or it can 

 be allowed to run down the proboscis upon 

 hard sugar in order to dissolve it, for the 

 latter is eaten with the proboscis, not with 

 the mandibles. 



The large glands (Fig. 6, IGI) situated in 

 the front part of the head are supposed, by 

 some students of the bee, to form the wliite 

 pasty brood food and the royal jelly. Others 

 think that these substances come from the 

 stomach. More investigation of the subject 

 must be made, however, before the question 

 can be decided ; but the contents of the 

 stomachs of workers have no resemblance 

 to the brood food. 



The circulatory system is very simple, con- 

 sisting of a delicate, tubular, pulsating heart 

 (Fig. 1, Ht) in the upper part of the abdo- 

 men, of a single long blood-vessel, the aorta 

 {Ao) , extending forward from the heart 

 through the thorax into the head, and of 

 two pulsating membranes, the dlaphrae,ms 

 {DDph and VBph) , stretched across the 

 dorsal and ventral walls of the abdomen, 

 but leaving wide openings along their sides 

 between the points of attachment. The 

 heart consists of four consecutive chambers, 

 Iht-Jfht, which are merely swellings of the 

 tube, each having a vertical slit or ostium 

 {Ost) opening into each side. The blood 

 is the colorless liquid that fills the spaces 

 about the viscera of the body cavity. The 

 dorsal diaphragm and the heart pulsate for- 

 ward. The blood in the cavity above the 

 former enters the ostia of the heart, and is 

 pumped forward through the aorta and out 

 into the cavity of the head. From here it 

 percolates back through the thorax and 

 enters the space beneath the ventral dia- 

 phragm {VDph) of the abdomen. This 

 membrane pulsates backward, and the blood 

 is driven posteriorly and upward, through 

 the lateral openings, around the abdominal 

 viscera, and again into the dorsal or peri- 

 cardial cavity of the abdomen, where it 

 begins its circulation anew. In insects the 

 principal function of the blood is to distrib- 

 ute the food which dissolves into it from the 

 alimentary canal. 



The respiratory system is very highly de- 

 veloped in the bee, consisting (Fig. 1) of 

 large air-sacs {I'raSc, l-io) in the lie ad, 

 thorax, and abdomen, and of tubes called 

 tracheae given off from them {Tra, LTra). 

 Fig. 1 shows principally the parts in only 

 the right side of the body. In the abdomen 

 a large sac {10) lies on each side connected 

 with the exterior by short tubes opening on 

 the sides of the first seven segments. Three 



