84 



THE BBB-KEEPBR'S GUIDB, 



worker is much larger than that of either the drone or queen. 

 The ganglia along the cord are the seat of reilex acts the same 

 as is the gray matter of our own spinal cord. Indeed, the 

 beheaded bee uses its members much more naturally than do 

 the higher animals after they have lost their heads. This may 

 arise from their more simple organism, or from a higher devel- 

 opment of the ganglia in question. 



The organs of circulation in insects are quite insignificant. 

 The heart (Fig. 32, H) is a long tube situated along the back, 

 to which it is held by large muscles (Fig. 32, in), and receives 



Fig. 31. 



Fig. 30. 



Brain of Bee^ from Cowan. 



Nervous System of Worker Larva, 

 after Duncan . 



the blood at valvular openings (Fig. 32 o, 33 a,) along its sides 

 which only permit the fluid to pass in, when, by contraction, it 

 is forced toward the head and emptied into the general cavity. 

 Valves prevent the blood from flowing back (Fig. 33, b.) Thus 

 the heart only serves to keep the blood in motion. 



There are no vessels to carry the blood to the various 

 organs, nor is this necessary, for the nutritive fluid every- 



