136 MANUAL OF ANIMAL BIOLOGY 



honey-cells and the worker-cells are practically the same size and 

 both of these types may be used for storing the honey. The 

 attachment-cells are irregular in shape, and serve to attach the 

 mass of the honeycomb to the sides of the hive. 



The workers obtain various substances from the flowers. In 

 the first place, they collect the nectar which is secreted in a liquid 

 form at the base of the flower. This is secured by the long tongue 

 in connection with certain mouth parts as previously described. 

 It is taken into the body and temporarily stored in the honey sac. 

 When the hive is reached the nectar is regurgitated and placed in 

 the cells. These are not capped at once, and certain workers, by 

 the vibration of their wings, cause the evaporation of a considera- 

 ble part of the water in the nectar leaving a concentrated syrup 

 which is honey. The flavor of honey depends upon the flowers 

 from which the nectar was collected. Some of the flowers which 

 supply the nectar for the best honey are those of White Clover, 

 Buckwheat, and Alfalfa. 



In addition to the nectar for honey manufacture, the Bees 

 gather great quantities of pollen which constitutes one of their 

 principal foods. Pollen is rich in nitrogenous compounds which 

 are not present in the honey, and it is therefore necessary that the 

 Bees have it as the basis of their food. Another material that is 

 collected from various trees is bee glue, or propolis, which is a 

 gummy, resinous substance. The Bees use it to cover the in- 

 terior of the hive and to fill the cracks. 



There are various matters of sanitation that must be looked 

 after if a hive is to be kept in a healthy condition. This is due 

 to the fact that there are so many Bees living in close quarters. 

 Any waste materials or dead animals are removed by workers 

 which are delegated for that purpose. Fresh air must also be sup- 

 plied. This is accomplished by certain of the workers who stay 

 at the entrance of the hive and draw in a current of fresh air by 

 keeping their wings in motion. Other workers act as sentinels at 

 the entrance and so guard the hive. 



III. INSECTS IN GENERAL 



A. Polymorphism in Insects 



In the study of the Bee it has been seen that a certain amount 

 of structural differentiation exists between the queen and the 



