CONTENTS. 



vii 



Page 



LETTER XXIV. 



Noises produced by Insects - 501 — 329 



While in motion - - - - 301 



While feeding, &c. - 308 



In calling, commanding, or giving an alarm - - 309 



As expressive of fear, anger, sorrow, love, &c. - - 313 

 By Beetles ----- 314 



Field Bugs - - - - 314 



Moths - - - - - 315 



Bees, &c. - - - - 316 



Grasshopper tribe - - - - 317 



Crickets < - - - 318 



Locusts, &c. - - - - 323 



Cicadae, &c. - - - 324 



LETTER XXV. 



Luminous Insects - 330 — 347 



Glow-worms - 330 



Fire-flies - 333 



Other luminous Beetles - 337 



Lantern-flies - - - - 337 



Other luminous insects - 339 



Source of their luminous property - 342 

 Its remote cause ----- 344 



Its use - 346 



LETTER XXVI. 



Hybernation of Insects ;- 348 — -375 

 In the egg state ----- 349 



pupa state - - - - 351 



larva state - - - - 352 



perfect state - ■■ - - 353 



Time of hybernation - 354 



Site of hybernacula - 355 



Solitary and social hybernation - 356 



Hybernation in several states - - - 356 



Torpidity produced by cold - 357 



Variations of torpidity - 357 



Some insects never torpid - 3Q0 



State of the Hive-bee in winter - 360 



Power of resisting cold by insects in different states - 364 



Cause of this power - 367 



Resumption of activity - 368 



Cause of hybernation - - « - 371 



