RAT-TAILED LARVAE. 



167 



Reaumur first beheld them, he gave them the 

 name of Vers a queue de rat ; that is, larvae with a 

 rat's tail ; and when the reader 

 looks at them, as shown in the 

 representation annexed, he will 

 be inclined to think with us, 

 that a more appropriate title 

 could not have been found. 



On watching them they will 

 be seen to wriggle about until 

 they are comfortably settled, 

 darting from place to place, as 

 if uneasy in their new position 

 and in the pure element. By- 

 and-by, however, they become 

 reconciled to their lot, and 

 lie perfectly quiet at the bottom of the glass in 

 the position represented. From the tail of each 

 will now be seen to rise a beautifully delicate and 

 minute tube, which comes up to the surface of 

 the water, and here, whatever be the movements 

 of the larva below, it remains floating and free. 

 Just as the diver may, while his companions 

 above are pouring down torrents of fresh air, 

 move about, and perform various duties under, 



Rat-tailed Larva: . 



