517 



semiualis. vsc. : Vesicle, w.l-w.2 : AYings. w.d. : Imagiiial disc 

 of wing. w.i. : Wing insertion, w.m. : "Wing" muscles, w.m.b. : 

 "Wing" muscle band. x. : Various structures referred to in t-ext. 



DESCRIPTION OF PLATES. 



Plate XV. 



Fig. 1. Larv-a of Nasonia towards end of first instar, in 

 [ventra] view. The muscles are shown on one side; on the other 

 [are seen the respiratory vessels. The nerve cord is also visible 



Fig. 2. Larva at end of feeding period (x55), showing the 

 [fifteen imaginal discs of the integument (heavily shaded), one 

 (pair) in each segment. The respiratory system is also seen; the 

 I alimentary canal is shown in outline. 



Fig. 3. Anterior end of larva at time of defaecation (xl50). 

 iMetamorphosis has commenced, and the various appendages are 

 [clearly seen through the transparent lai*val sheath. Note the 

 fat-body showing up through the integument; note also the 

 {mandibular palp. 



Fig. 4. Abdomen of imago, in ventral view. The numbers 

 refer to the alxiominal segments. 



Fig. o. Integumental imaginal disc of larva shown in fig. 2 

 |(xl80), showing the invaginated leg anlage. 



Fig. 6. Anlage of leg, from the same specimen, viewed in 

 [optical section (x300). Note the mesoderm extending into the 

 IhoUow appendage, 



Plate XVI. 



Fig. 7. Fresh pupa (xoO), showing migration of first two 

 abdominal segments. 



Fig. 8. The same, four days later (x 50). Note the exten- 

 sive shrinking that has occurred. Note also final position of 

 migrated abdominal segments. 



Fig. 9. VicAv of propodeum and adjacent segments of pupa 

 two days old (x70). Note the migrated abdominal segments; 

 also the complex wing insertions. 



Fig. 10. Transverse section through first thoracic segment 

 of lai*^^a in first instar (xlOOO). The complete section has not been 

 drawn. Notice the imaginal elements in the integument, nerve 

 cord, and intestine. 



Fig. 11. Antennae of female wasp, imago (xl20). The 

 bristles are not shown. Note the auditory organs. 



Fig. 12. Head of metamorphosing larva, about 17 hours 

 before pupation, i.e., seven hours later than fig. 3 (xl50). 



Plate XVII. 



Fig. 13. Head of mature larva at cessation of feeding, 

 viewed ventrally, and slightly from one side, showing all the 

 imaginal discs of the mouth appendages (xl69). Note the double 

 nature of the labrum; also the true antenna (ant.), which later 

 disappears. Mandibular palps are not visible with certainty. 



Fig. 14. Mouth appendages of pupa aged two days (xl50). 

 Note shrinking within the pupal sheath. 



Fig. 15. Longitudinal section of part of the antenna of 

 thirty-six hour pupa (x450). 



