BUTTERFLIES AND BEES 33 



and nectar from flowers. Thus the division of labor is not be- 

 tween one kind of individual and another, but between one 

 period of life and another — like the division of labor in some 

 factory in which the younger workers make the parts for the 

 manufactured product and the older workers assemble the parts. 



27. Interdependence. The division of the total work of the bee- 

 hive or the ant nest has been compared ( i ) to the similar divi- 

 sion of labor among human beings in society and (2) to the 

 division of functions among the organs of any plant or animal. 

 The individual bee, for example, continues to live by carrying 

 on many fairly distinct processes— eating, breathing, feeling, 

 moving, and so on. We have already seen that there are special 

 organs that carry on these special processes. The mouth is a 

 food-taking organ ; the leg an organ of locomotion ; the eye a see- 

 ing organ ; and so on. Now, in the case of a single organism, as 

 in the case of a colony or society, division of labor means the 

 dependence of one part upon all the others. The mouth can 

 take in food only if the wings bring the insect to the flower. 

 But that in turn depends upon the eye seeing the flower. More- 

 over, the wings and the eye and the mouth cannot do their work 

 unless the food taken in by way of the mouth is somehow 

 changed into a usable form and then distributed to the muscles 

 of the wings, the nerves of the eye, and the complex machinery 

 of the mouth. And, finally, the parts have to work in harmony 

 or balance, and their activities have to be timed so that they fit 

 together effectively. There is thus a certain interdependence 

 among the parts, as well as a correlation. 



This idea of interdependence applies not only to the relation 

 among the parts of the organism or among the members of a 

 colony or society ; we see it illustrated also in the dependence 

 of different species upon each other. The bee, for example, de- 

 pends upon the clover for pollen and nectar to make food and 

 wax. The clover species, in turn, depends upon the bee to 

 render the important service of transportation. The forma- 

 tion of seeds in flowers remains in many species impossible un- 

 less some insect first carries the pollen from the organ in which 



