Page 



The Midgut 436 



The Rectum 436 



The Salivary Glands 436 



The Hepatic Caeca ... ... 437 



The Post-embryonic Development of the Intestine 437 



Metamorphosis of Foregut ... ... ... ... 437 



Metamorphosis of the Midgut and the Develop- 

 ment of the Post-oesophageal part of the 



Foregut 440 



Metamorphosis of the Hindgut ... ... ... 444 



The Rectal Glands 446 



The Malpighian Tubes 447 



The Salivary Glands 449 



General Remarks ... ... ... ... ... 450 



F. The Ductless Glands 451 



The Oenocytes ... ... ... .... ... ... 451 



The Lateral Intestinal Glands ... ... ... ... 454 



The Dorsal Abdominal Glands ... ... ... ... 455 



G. The Fat-body 456 



Structure and Metamorphosis of Fat-body ... ... 456 



Function of the Fat-body 461 



H. The Gonads ... 462 



Male Organs 462 



Female Organs ... ... ... ... ... ... 465 



I. The Nej-vous System 472 



Introduction ... ... ... ... ... ... 472 



The Ventral Nerve Cord and Peripheral Nerves of 



the Nasonia Larva ... ... ... ... ... 473 



The Post-embryonic Development and Meta- 

 morphosis of the Ventral Nerve Cord ... ... 474 



The Brain: its Structure and Metamorphosis ... 478 



J. The Vascular System ... ... ... ... 484 



The Blood 484 



The ''Heart" ... 487 



Structure of the Lar\^al Heart ... 488 



Metamorphosis of the Heart ... ... ... 489 



K. Appendix — 



The Degeneration Processes of the Larval Cells of 



Nasonia ^ ... ... ... ... ... ... 490 



Part II. 



On the Physiology and Interpretation of the Insect 



Metamorphosis ... 492 



Summary ... ... 504 



Bibliography 511 



