72 PHYSIOLOGY OF THE HONEY-BEE. 



To return to Bevan : 



169. " When it has undergone this change, it has usually borne 

 the name of nymph, or pupa. It has now attained its full growth, 

 and the large amount of nutriment which it has taken serves as 

 a store for developing the perfect insect. 



" The working-bee nymph spins its cocoon in thirty-six hours. 

 After passing about three days in this state of preparation for a 

 new existence, it gradually undergoes so great a cli.uige as not 

 to wear a vestige of its previous form." 



Fig, 29. 



BPINNIffG OF THE COCOON AND TRANSFORMATION INTO NYMPH. 



(Maguifled. From Sartori and Ranschenfels.) 



170. The last cast-off skin of the larva, " which, by Ihe 

 creature's movements within the cell, becomes plastered to 

 the walls and joins the cocoon near the mouth end " (Chesh- 

 ire), is left behind, and forms a closely-attached and exact 

 lining to the cell ; by this means the breeding-cells become 

 smaller, and their partitions stronger, the oftener they 

 change their tenants. 



So thin is this lining, that brood combs more than twenty 

 years old have been found to raise bees apparently as large 

 as any other in the Apiary. 



171. About twenty-one days are usually required for the 

 transformations from the worker -egg to the perfect insect. 

 But the time may be shortened or lengthened by the tem- 

 perature, or the conditions of the colony. Dzierzon and 

 others wrote that a worker-bee can hatch in nineteen to 

 twenty-one days. Collin says nineteen to twenty-three. 

 That the brood can remain even longer before hatching, is 



