PUPJE WITH AN AIR-TUBE. 249 



upwards, anxiously seeking to thrust its tubes into 

 the air. In the larva state the gnat breathes by 

 its tail, in the pupa state by its head! The pupae 

 of some aquatic insects breathe like the larvae 

 of the same insects by organs like gills. That of 

 the ephemera shown on the last page is an 

 instance. 



The curious apparatus of a telescope-like air- 

 tube of the rat-tailed insects, described in a former 

 page, will not be forgotten by the reader. It may 

 interest him to learn that there is another little 

 creature which, in the pupa state, is furnished with 

 a somewhat similar apparatus. These pupae have 

 not the same power of swimming with the last, 

 and therefore require a special provision to meet 

 the necessities of their case. They are plunged 

 some way down in the water, and air is conveyed 

 to them by a hollow tail-like tube, which is always 

 found to open on the surface of the water. It is 

 a curious thing to contemplate these little crea- 

 tures, so beautifully provided for in this manner. 

 Secure of all they need in the supplies of air fur- 

 nished to them by their tube, they rest peacefully 

 in the waters, unmoved by any of the accidents 

 which occur to surrounding creatures, and pa- 



