292 NATURAL HISTORY OF AQUATIC INSECTS CH. 



a distance, there is no better way than tying to- 

 gether stems of the great reed, and causing the larvae 

 to creep into them. 



" The body of the larva is divided into fourteen 

 distinct segments. The first forms the head, the 



o 



three next the thorax, and the 

 remaining ten the abdomen. 

 Upon the head are seen the 

 eyes, and just beneath them the 

 delicate antennae, divided each 

 into five joints ; below these are 

 the mandibles, and again below 

 these the hairy, membranous 

 maxillae, which are like those of 

 Crabs or Shrimps. The first 

 pair of thoracic limbs are adapt- 

 ed by their shape for digging. 

 Their most powerful action is 

 outward, and in this way they 

 are able to throw out the mud 

 as a Mole throws out earth. 

 Each of the fore-feet is formed 

 of four joints and a single claw. 

 The second thoracic segment is 

 protected above and below by 



a shield-like plate ; it bears a pair of limbs, each 

 consisting of five joints and a claw, and on the 



probably is this. Under natural conditions the larvae of Palin- 

 genia inhabit slowly running water, which not only supplies 

 dissolved air for respiration, but brings down the food upon 

 which they subsist. The captives were no doubt kept in vessels 

 of standing water. Few aquatic animals can long survive the 

 change from running to standing water. 



FIG. 90. Larva of Palingenia 

 longicauda, male. From 

 Swammerdam, Biblia Na- 



