The Honey Bee and the Fly 



363 



in turn open into a pair of large mucous glands which unite. It is at 

 this union that the ejaculatory duct begins. This duct ends in the 

 copulatory organ. 



The sperm of the male are placed in the spermatheca (seminal re- 

 ceptaculum) of the queen by a single drone, where they remain alive 

 for many years, in fact as long as the queen lives and lays eggs. While 

 the average life of a queen is probably from three to four years, there 

 is on record a queen which continued laying fertile eggs for thirteen 

 and a half years. 



About five to eight days after' emerging from the comb-cell, a queen 

 leaves the hive. First, she crawls about and takes very short flights, 

 and then goes on a nuptial trip of about thirty minutes. One of the 

 drones copulates with her during the nuptial trip, after which the queen 

 returns to the hive. 



The eggs are bluish-white and oblong in shape. They are fertilized 

 just before leaving the queen's body. The eggs are deposited at the base 

 of the cells and then fastened into position in the cells by a secretion. 

 Fertilized eggs are laid in cells that have already been arranged to 

 receive them, some being in queen cells, and some in worker cells, while 

 unfertilized eggs are placed in drone cells. But there seems to be 

 evidence that mistakes are made, and the right type of egg is not always 

 placed in the right cell. 



EMBRYOLOGY 



After the nuclei of the sperm and egg have united into a single 

 nucleus, a chitinous covering, the chorion, surrounds the entire egg. As 

 cleavage takes place, no definite cell walls appear. This means that a 

 great mass of protoplasm is present with many nuclei. These nuclei 



migrate to the periphery to form a 

 single layer of cells, called the blas- 

 toderm, while the remaining portion 

 of the yolk remains as yolk-sub- 

 stance until it is converted either 

 into food for the developing em- 

 bryo, or into further cellular sub- 

 stance. 



A germ-band or primitive streak 

 (Fig. 237) now forms on one side of the egg where the blastoderm 

 becomes thickened. This is to become the ventral side of the bee. The 

 brain develops separately. A median groove arises in the germ-band, 

 and so two germ layers are formed, an outer layer called the ectoderm, 

 and an inner known as the entomesoderm. It is the latter layer from 

 which both entoderm and mesoderm arise. The germ-band then grows 

 around the entire egg. 



It is of interest to know that, while the antennae and four pair of 



Fig. 237. 



Cross section of germ-band of Clytra at 

 ^astrulation. g., germ-band; i., inner layer. 

 (After Le'caillon.) 



