XIV LIST OF ILLUSTRATIONS. 



FIGURE PACK 



tile hairs ; //, hypodermic cells ; M, the membrane stirronndincr 

 them ; K, nuclei of the olfactory cell ; K^^ remains of the 

 earlier upper nucleus ; SK, lower circle of rods ; RS, olfactory 

 rod ; GZ, Geisselzelle ; MZ, membrane forming cell ; M, mem- 

 brane closing the pit . . . . . . . . . . . . 55 



43. Diagram showing structures on the terminal segment of the 



antennae of insects, a, Chitinous cuticle ; 6, hypodermic layer ; 



c, ordinary hair; d, tactile hair; e, cone; /, depressed hair, 

 lying over g, cup, with rudimentary hair at the base ; A, simple 

 cup ; », champagne-cork-like organ of Forel ; A, flask-like 

 organ ; I, papilla, with a rudimentary hair at the apex . . 56 



44. Leg of Stenobothrus pratorum . . . . . . . . . . 62 



45. Sound-bow of Stenobothrus . . . . . . . . . . 63 



46. Diagram of human ear. D, Auditory canal ; E, mouth of Eusta- 



chian tube ; cc, tympanic membrane ; B, tympanic cavity ; o, 

 fenestra oralis ; r, fenestra rotunda ; s, semicircular canals ; 

 A, cochlea . . . . . . . . . . . . . . 78 



47. Ossicles of the ear. H, Hammer ; Am, anvil ; Am. k, shorter 



process of the anvil ; Ain. I, longer process of the anvil ; S, 

 stirrup; S^, long process of the hammer .. .. . . 7S 



48. Section through the ampulla. N, nerve ; z, terminal cells ; h, 



auditory hairs . . . . . . . . . . . . . . 79 



49. Tympanal wall of the ductus cochlearis, from the dog. Surface 



view from the side of the scala vestibuli, after the removal of 

 Reissner's membrane, ^2. I. Zona denticulata Corti. II. Zona 

 pectinata Todd-Bowman : 1, Habenula sulcata Corti ; 2, Ha- 

 benula denticulata Corti ; 3, Habenula perforata Kolliker. 

 in. Organ of Corti : a, portion of the lamina spiralis ossea 

 (the epithelium is wanting) ; b and c, periosteal blood-vessels ; 



d, line of attachment of Reissner's membrane ; e and e^, epi- 

 thelium of the crista spiralis ; /, auditory teeth, with the 

 interdental furrows; g, g,, large-celled (swollen) epithelium 

 of the sulcus spiralis internus, over a certain extent shining 

 through the auditory teeth ; from the left side of the pre- 

 paration they have been removed ; h, smaller epithelial cells 

 near the inner slope of the organ of Corti ; k, openings through 

 which the nerves pass ; i, inner hair cells ; ?, inner pillars ; 

 m, their heads ; o, outer pillars ; n, their heads ; p, lamina 

 recticularis ; q, a few mutilated outer hair cells ; r, outer 

 epithelium of the ductus cochlearis (Claudius's cells of the 

 author's) ; removed at s in order to show the points of attach- 

 ment of the outer hair cells . . . . . • . • . . 80 



