278 READINGS IN BIOLOGICAL SCIENCE 



planets. Where the two creatures resemble one another, we often seek some 

 other explanation than that of common ancestry. Usually it is due to adjust- 

 ment on the part of the bee to the same world as that in which we live and 

 to which we are adjusted. For life is adjustment, and any serious lack of 

 adjustment quickly leads to death. 



Our common ancestor was without any means for breathing air or for 

 motion on land or for resistance to the desiccating effect of dry air, or for 

 terrestrial hearing or smelling or seeing. It follows therefore that the ad- 

 justments of men and bees to terrestrial Hfe have been achieved quite inde- 

 pendently of each other. 



As to breathing, we "draw air" into our lungs, there load the blood with 

 oxygen and then pump it throughout the body to carry oxygen to the 

 tissues. The insect has a system of fine air tubes whereby the air itself is 

 carried to every part of the body. For motion the bee has six limbs to our 

 four, and surpasses us completely by the possession of four wings. But her 

 limbs so closely resemble ours — made up of two long pieces and a set of 

 small pieces at the foot — that we not only speak of the legs and the feet of 

 the bee, but we call the parts femur, tibia and tarsus. Obviously this re- 

 semblance is strictly superficial. It is not due to common ancestry, but to 

 the mechanical nature of the world we inhabit. 



The skeleton of the bee consists entirely of her hard outer shell, which 

 serves in place of bones. This shell also serves to prevent desiccation. Our 

 bones are inside us, and consequently we must have a special waterproof 

 skin to keep us from drying up. The powerful muscles of the bee are at- 

 tached to prongs and bars of the shell, which often project far into the 

 insect's body. That this method is adequate is proven by the legs of the 

 grasshopper and the wonderful flight of many higher insects. Once I saw 

 a worker bee grasp a dead bee by her legs and fly up as high as the house 

 and over a neighbor's lot before dropping her load. The muscles of the bee 

 are "striped" exactly as are the voluntary muscles of the vertebrates. No 

 worms have such muscles. 



The eye of the bee is too complex to describe in detail, but it depends 

 upon the lens-shaped bodies of dense refractive material which focus the 

 rays of light. Of course, this is an adjustment to the nature of light-waves 

 in relation to solid bodies. The food of the bee consists of nectar, or honey, 

 and pollen, the latter being the richest bit of protein that plants produce. 

 Why has man never found a way of eating pollen? I have tried it but with- 

 out success; it didn't taste good. The nectar of flowers is mostly a very 

 thin solution of cane sugar which the bee sucks up and swallows into a 

 special pouch called the crop. The crop connects with the throat of the 

 bee, as our lungs connect with our esophagus. In the crop later, the cane 

 sugar is partly inverted or predigested, becoming dextrose and levulose. 

 This is exactly the effect of human digestion upon cane sugar. 



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