PSE UDOXE CROP TERA . 



71 



clasping organs. The most remarkable peculiarity of the order is 

 the fact that the copulatory organs of the male are distinct from the 

 opening of the vasa cleferentia ; the former are situated on the 

 second abdominal segment, the latter on the ninth. Before pairing 

 the male conveys the seminal fluid to a bladder-like cavity on the 

 second abdominal segment ; this is done by bending the tip of the 

 abdomen forward. The pairing takes place during flight. The 

 male seizes the neck of the female with his anal clasping organs : 

 the female then curves the end of her abdomen to the organs on the 

 second abdominal segment of the male 



The eggs are laid in water. In some species the female flic- 

 back and forth over the surface of the water, sweeping down at in- 

 tervals to touch it with the tip of her abdomen, and thus wash off 

 one or more eggs into it. In other cases the eggs are laid in a mass. 

 On one occasion, in company with my class, I saw a dragon-fly pois- 

 ing herself in the air a short distance above the point where a water- 

 plant emerged from the water. At frequent intervals the insect de- 

 scended with a swift curved motion, pushing the end of her abdomen 

 into the water. On examination a large cluster of eggs were found 

 attached to the plant just below the surface. Professor Uhler has 

 observed a dragon-fly alight upon a water-plant, and, pushing the 

 end of her body below the surface of the water, glue a bunch of 

 eggs to the submerged stem or leaf. 



The nymphs of dragon-flies (Figs. 68 and 69) pass their lives in 



Fig. 68.— Nymph of Dragon-fly, Agrioninx-. Fig. 69.— Exuviae of nymph of Dragon-ily. 



the water. They are predacious, feeding on such aquatic animals 



