X List of Illustrations 



FIGITKE PAGE 



24. Trematode worm or fluke. (After Thompson) . . .145 



25. Lungs of a domestic fowl. (Original) 147 



26. Diagrammatic drawing of the left lung of a fowl. (Original) . 148 



27. Ventral surface of right lung of a fowl. (From Gadow, after 



Stieda) 149 



28. Cross section of small air tubes of the lung of a goose. (From 



Oppel, after Schultz) 150 



29. Fowl's head showing infra-orbital tumor caused by roup. (After 



Roebuck) 157 



30. Showing appearance of a hen a day before death from roup. 



(After Harrison and Streit) 158 



31. Diphtheritic roup or canker. (After Roebuck) . . . 166 



32. Aspergillus fumigatus. (After Mohler and Buckley) . . 176 



33. Cytodites mudus, the air-sac mite. (After Theobald) . . 181 



34. Bird suffering from spirochcetosis. (After Kolle and Hetsch) . 191 



35. Fowl spirochetosis. (From Kolle and Hetsch, after Barri) . 192 



36. T\\Q common hew louse, Menopon pallidum. (From Banks) . 206 



37. Lipeurus variabilis, a louse that infests poultry. (From Banks, 



after Denny) 207 



38. Goniodes dissimilis, a louse that infests poultry. (From Banks, 



after Denny) 207 



39. Feathers showing eggs or "nits" of the common hen louse. 



(Original) 208 



40. The common "red mite" of poultry, Dermanyssus gallince. 



(After Osborn) 214 



41. Normal leg and leg of hen affected with scaly leg. (After 



M^gnin) 217 



42. Leg of hen severely affected with scaly leg. (After Haiduk) . 219 



43. Adult female of the mite Knemidocoptes (Dermatoryctes) mu- 



tans. (After Haiduk) 220 



44. Six-legged larva of Knemidocoptes {Dermatoryctes) mutatis. 



(After Haiduk) 221 



45. Section of the skin of the leg of a fowl affected with scaly leg. 



(After Haiduk) 223 



46. Egg containing female of Sarcoptes IcBvis var. gallince. (After 



Theobald) 225 



47. Symplectoptes cysticola, coimective tissue mite. (After Theo- 



bald) 227 



48. "Harvest bug," Tetranychus (Leptus) autumnalis. Larval 



form. (After Murray) 227 



