Vlll 

 CHAPTER 



COX TENTS. 



Sec. 3. The Exo-skeleton of the Proboscis - - - 127 



a. General Morphology - - - - 127 

 d. The Sclerites and Morphology of the Proboscis of 



the Blovv-Hy - - - - - i34 



c. The Proboscis of the Immature Imago - - 148 



d. Comparative Anatomy of the Proboscis in the 



Diptera - - - - - - 149 



Sec. 4. The Thoracic Exo-skeleton - - - - 1 54 



a. (jeneral Morphology - - - - i54 



Ik General Description of the Thoracic Skeleton of 



the Blow-Hy - - - - - 166 



c. The Sclerites of the Thoracic Skeleton - - 171 



d. Details of the Exo-skeleton of the Legs - - 190 

 <?. The Wings and Mechanism of Flight - - 198 



Sec. 5. The Exo-skeleton of the Abdomen - - - 209 



a. General Morphology . . . . 209 



b. The Abdominal Skeleton of the Plow-Fly - - 210 

 Appendix to Chapter V.— Methods of Study - - -211 



VI. The Topographical Anatomy of the Muscles and 



Viscera of the Imago ----- 215 



VII. The Embryology of the Blow-Fly in the Egg - - 230 

 Sec. I. Early Changes in the Ovum subsequent to Fertilization 



and Formation of the Blastoderm - - 230 



„ 2. Formation of the Membranes and Primitive Band - 241 

 „ 3. Origin of the Archenteron, Somatopleure and Coelomic 



Sacs ------- 247 



,, 4. The Dorsal Organ of Kowalevski - - - 254 

 ,, 5. The Xymphoid Stage of the Embryo, and its Con- 

 version into the Larva - - - - 257 



VIII. General Anato.my and Histology of the Blow-Fly - 262 



Sec. I. Cells and Nuclei - . . - - 264 



„ 2. The Parablastic Tissues . - - - 270 



„ 3. Epithelia ...... 277 



„ 4. Muscles and Nerves ----- 282 



a. The Muscles . . . - . 282 



b. The Nerves - - - - - - 288 



IX. The Development of the Nymph in the Pupa - - 292 



Sec. I. Formation of the Pronymph from the Larva - - 296 

 a. Histolysis of the Larval Muscles - - - 297 

 l>. The Histolysis of the Hypodermis, and the For- 

 mation of the Paraderm - - - - 299 



c. Relation of the Imaginal Discs to the Paraderm - 303 



d. The Contraction of the Paraderm and Evolution of 



the Discs ------ 305 



