of 



6 THE MYRMELEON TRIBE. 



These are contained in two large packets, each con- 

 taining from 300 to 400, which are both extruded 

 from the body at the same time, through two open- 

 ings formed for the purpose, and they fall together, 

 in one accumulated mass, upon the water. Td ena- 

 ble the creature to extrude these, and at the same 

 time to fiil up the great vacuum in the abdomen, 

 that must instantaneously take place, the fly is pro- 

 vided with a couple of small bladders, which it has 

 the power of filling with air. 



The singular quickness and ease with which 

 these little creatures strip themselves of the slough 

 of the nymph, in order to become flies, is very sur- 

 prising. We do not draw our arm more quickly 

 from the sleeve of a coat, than the Ephemerae draws 

 its body, its wings, its legs, and the long filaments 

 of its tail, from that complicated vestment which 

 forms a kind of sheath for all these parts. No 

 sooner is a rent effected in the corcelet, and the 

 body seen through that rent, than the rest of the 

 operation is finished in an instant. Sometimes, in- 

 deed, it happens that the filaments of the tail can- 

 not be so quickly disengaged as the rest of the body. 

 In this case, the insects fly away with their slough 

 appended : and sometimes also these slender fila- 

 ments are broken oft'. 



THE MYRMELEON TRIBE. 



THE antennas of these insects are about the 

 length of the thorax, and thickest at the tip. The 



