THE OVARIES AND EGG-TUBES 



503 



(Ovaries of Coleoptera, with the exception of the Geodephaga and Hydra- 

 dephaga, and Aphidse in part. ) 



3. Comprising ovaries whose ends above the egg-germs contain a well-devel- 

 oped mass of cells functioning as a yolk-forming organ, between whose special 

 elements grow root-like 

 offshoots of nearly ripe 

 egg-cells. (Hemiptera.) 



When the egg is ripe 

 the food-chamber dis- 







appears because its 

 contents have served 

 for the formation of 

 the egg below it. In 

 Lepidoptera especially, 

 the egg-tubes resemble 

 strings of pearls be- 

 cause most of the nu- 

 merous eggs ripen 

 simultaneously and are 

 likewise deposited at 

 the same period, which 

 is naturally not the 

 case in those insects 



whose eggS gradually FIG. 477. A, lower portion of one of the two ovaries ol 



, jrrrr\ T ^P h inx fi0u8lri, the four egg-tubes uniting to form the slightly 



ripen (llg. 477). In de veloped calyx (OK). The egg-tubes above contain ripe eggs 



. still surrounded by the follicle ; e. c, the empty egg-chamber. 



Other Cases the egg- Or Beyond the empty egg-chambers (e. c) are three egg-chambers 



, with ripe eggs and the connecting cord. The whole tube is sur- 



lOOd-COmpartinentS are rounded by the peritoneal membrane and musculature. After 



transformed into each 



other, but only one egg- and one food-compartment can be situated 

 in the same dilatation of the ovarian tube. Finally, there are insects 



in whose egg-tubes the egg-compartments are 

 arranged in a single row, while the capacious 

 terminal chamber contains a large mass of 

 food-cells. 



Egg-cells, nutritive cells, as well as the 

 cells of the follicle epithelium (epithelium of 

 the chambers of the ovarian tubes), originate 

 as similar or homologous elements, division of 

 labor leading to their later differentiation. 

 Only a few of the numerous egg-germs de- 



FIQ. 478. Ovary of a . -, 



beetle, drawn somewhat dia- Velop into 6ggS, the rest Serving as envelopes 

 grammatically : o, egg -tube; n n _r> i r j_i r /T 



, stalk of the same ; c, egg- and also as food tor these tew. (Lang.) 



viduct ' ' After In many insects the egg-tubes open into an 



--S 



