19. Sound-making organs and ears of a conehead katydid 35 



20. Auditory organ of a katydid 37 



2i. A bush katydid 38 



22. The oblong-winged katydid 40 



23. The angular-winged katydid 42 



24. The true katydid 44 



25. The katydid in various attitudes 45 



26. Sound-making organs of the katydid 48 



27. A conehead katydid 50 



28. The robust katydid 51 



29. The common meadow katydid 52 



30. The handsome meadow katydid 53 



31. The slender meadow katydid 53 



32. The Coulee cricket 55 



23. Wings of a tree cricket 56 



34. A mole cricket 57 



35. The striped ground cricket 59 



36. The common black cricket 61 



37. The snowy tree cricket 64 



38. Antennal marks of the tree crickets 66 



39. The narrow-winged tree cricket 67 



40. A broad-winged tree cricket 68 



41. Back glands of a tree cricket 68 



42. The jumping bush cricket 70 



43. The common walking-stick insect 71 



44. A gigantic walking-stick insect 72 



45. A leaf insect 73 



46. The praying mantis 74 



47. A shield-bearing mantis 75 



48. Egg case of a mantis 75 



49. Common household roaches 78 



50. Egg cases of roaches 79 



51. Young of the Croton bug 81 



52. The house centipede 83 



53. Wings of a cockroach 84 



54. A Paleozoic forest 86 



55. Fossil roaches 90 



56. Early fossil insects 91 



57. Machilis 93 



58. Dragonflies 94 



59. A young dragonfly 96 



60. A mayfly 97 



61. A young mayfly 98 



62. The relation of the germ cells and body cells .... 100 



63. External structure of an insect 102 



64. Leg of a young grasshopper 103 



65. Legs of a honeybee 10^ 



