2 3 2 



OUR HOUSEHOLD INSECTS 



of sculling apparatus. 



together under a thin skin, sufficiently transparent 



for the individual 

 parts to be traced 

 from without, as 

 shown in the photo- 

 graph ; the "tail" 

 is, of course, the 

 abdomen, and it is 

 terminated by a 

 couple of broad 

 leaf - like paddles 

 (Fig. 73) of ex- 



FlQ. 73. Terminal paddle or leaflet of pupa of a nn : 51 > p cfvnr>hirp 

 species of Gnat (Corethra plumicornis). quiSlte Struct .re, 



which form a sort 

 It no longer jerks about head 

 downwards, but, turning a 

 somersault, passes the next 

 stage of its life right way 

 up, notwithstanding its ap- 

 parently top-heavy shape. 

 Conformably with the altered 

 position, though whether as 

 cause or consequence it is 

 not easy to say, the opening 

 to the breathing organs is now 

 on the thorax. Two horn-like 

 projections (Fig. 74) are here 

 seen, which are the prolonged 

 lips of the spiracles. Into 

 these is taken, by periodical 

 visits to the surface, what- 

 FIG. 74 .-s P iracuiar horn of same ever air may be necessary for 

 breathing purposes; such 

 visits are, however, by no means frequent, the insect 



