TJic Nymph. 



l^ 



First, with regard to the breathing apparatus, which 

 is of more than ordinary interest, seeing that the earher 

 part of the insect's existence is aquatic, in which state 

 it breathes the air chssolved 

 in the water, while the 

 second part is aerial. Our 

 knowledge of the respiration 

 of the Dragonfly n\-mphs is 

 far from complete, but certain 

 facts ha\'e been well ascer- 

 tained. One of these is that 

 the Libcllulidci: breathe by 

 means of rectal branchiae. 

 The water is drawn in 

 through an opening between 

 the five anal appendages 

 (Fig. I I , lat. a.a., l.a.a., n.a.a.), 

 which are then brought to- 

 gether so as to close the 

 orifice. After the air has 

 been extracted, the water is 

 ejected, and this can be done 

 with such force as to propel 

 the insect through the water 

 at a \er\' considerable pace, 

 and it is b}' repeating this 

 process that the n\'mph 

 moves about rapidl}-, though 



in a series of jerks. In place of the five-pointed 

 appendages the Agriouiiuc have three thin blade-like 

 lamellae (Fig. 12, c.L), which probably assist in respiration 

 as the}' possess a ramification of trachea:;, but are 



D 



Fig. II. — Nymph of an Axis- 

 DPTERiD Dragonfly 



(AXAX IMPERATOR). 



);;., Mask ; f., Vertex ; a.. Antenna ; 

 c, Eye; o., Occiput; /. 6./)., Position of 

 Leg-base Processes; p., Prothorax ; 

 m.s., Meso-thoracic Spiracle; k'.s., 

 Wing-slieaths; /., Femur; t., Tibia; 

 t.}.. Tarsal Joints; k., Ungues (or 

 claws) ; 4-10, Visible Segments ot 

 Abdomen ; m.p., Male Projection ; 

 u.a.a.. Upper Anal Appendage ; 

 lat. a.a., Lateral Anal Appendages; 

 l.d.a.. Lower Anal Appendages. 



