322 



PHYL UM A R TPIROPO DA. 



the common oviduct. 



Mating takes place only once in the life of the queen, 

 and is followed by the death of the drone. 



In the queen the large ovaries occupy considerable space in the ab- 

 dominal region. As usual, each consists of numerous (100-150) ovarian 

 tubes, containing ova in various stages of development. The ovarian 

 tubes open into the right and left oviducts, which again .unite to form 



With the anterior portion of the common duct 

 the globular spermatheca is associated. In con- 

 nection with it there is a gland corresponding to 

 the mucus gland of the male. The oviduct ter- 

 minates in a copulatory pouch. 



Previous to laying, the eggs are fertilised by 

 sperms set free from the spermatheca. In the 

 case of drone eggs, this liberation of spermatozoa 

 does not take place, and the eggs in consequence 

 are parthenogenetic. Queens which have never 

 mated, or which have exhausted their stock of 

 male elements, habitually lay drone eggs, but 

 those which are laying abundant fertilised eggs 

 at times also lay unfertilised eggs. This with- 

 holding of spermatozoa is said to be "voluntary," 

 and related to the needs of the colony, but the 

 physiological reason is unknown. 



The workers possess female organs similar in 

 type to those of the queen, but of an extremely 

 rudimentary nature. 



The eggs are laid singly in the cells of the comb, 

 at the rate of about two per minute, for weeks 

 together. They are of the usual insect type. 

 According to the size of the cell in which it is de- 

 posited, and the food with which it is furnished, 

 the fertilised ovum develops into a worker or into 

 queen. The development takes place within 



FIG. 160. One of 

 the Thysanura 

 (Campodea staphy- 

 l i >i u s). After 

 Lubbock. 



The hairs and bristles 

 have been removed. 



a 



the cell, and includes a complete metamorphosis. 



CLASSIFICATION OF INSECTS. 



I. Primitive wingless insects, Apterygota or Aptera, including 

 Thysanura, e.g. Campodea, Lepisuia ; Collembola ; Spring- 

 tails, e.g. Podura, Smynthurus. 

 II. Winged insects, Pterygota (in some degenerate forms the wings 



have been lost). 



A. With mouth-parts usually adapted throughout life for biting 

 (Menognathous), with no metamorphosis ( Ametabolic) or 

 with incomplete metamorphosis (Hemimetabolic). 

 e.g. Orthoptera (cockroach, locust, cricket, etc.); 

 Corrodentia (Termites, bird-lice) ; Odonata 

 (Dragon-flies); Ephemerida (May-flies); and 

 Dermaptera (Earwigs). 



