THE RIVER-SIDE NATURALIST. 



" The larvae of certain dragon-flies (^Eschna and Libellula)' 

 will afford you the most amusement by their motions. 

 These larvae commonly swim very little, being generally 

 found walking at the bottom on aquatic plants ; when 

 necessary, however, they can swim well, though in a 

 singular manner. If you see one swimming you will find 

 that the body is pushed forward by strokes, between which 

 an interval takes place. The legs are not employed in 

 producing this progressive motion, for they are then applied 

 close to the sides of the trunk in a state of perfect inaction, 

 but it is effected by a strong ejection of water from the 



B 



PUPA OF THE DRAGON-FLY. 

 A The mask extended. B Mask closed, and discharging a current of water. 



posterior orifice (see fig. B above). This is produced by 

 drawing the water in and then expelling it. As the larva 

 between every stroke of its internal piston has to draw in a 

 fresh supply of water, an interval must of course take place 

 between the strokes " (Kirby and Spence, " Motions of 

 Insects "). 



The author of the article " Insects " in the " Encyclo- 

 paedia Britannica " adopts metamorphosis as the basis 

 of classification of the Neuroptera. He says : " The 

 stumbling-block of all systems has been the Linnaean 

 order Neuroptera, inasmuch as its members combine the 

 characters of most of the other orders, and ingenious 



