DESCEIPTION OF PLATE I. 



Fig. 1. — Longitudinal section through the left hind-wing of the mature larva of 

 Pieris rapae. The plane of the section is parallel to the frontal plane 

 of the larva, i.e., perpendicular to its dorso-ventral axis. 



Fig. 2. — A portion of a cross-section of the larval wing of P. rapae. 



Fig. 3. — Longitudinal section (i.e., with the trend of the nervures) through the 

 pupal wings of Sainia cecropia. The section is taken near the 

 lower free edges of the pupal wing cases. 



Fig. 4. — Portion of a longitudinal section through the pupal cuticula and wing 

 tissue of (S. cecropia. Specimen killed in January. 



Fig. 5. — Portion of a longitudinal section through one of the young pupal wings 

 of Euvanessa antiopa. 



Fig. G. — Portion of a longitudinal section through a pupal wing of Anosia archip- 

 pus, about eight days before emergence. 



Fig. 7. — Portion of a longitudinal section through one of the pupal wings of 

 A. archippus about eight days before emergence. 



Fig. 8. — Portion of a longitudinal section through a pupal wing of A. archippus, 

 about five days before emergence. 



Fig. 9. — Portion of a cross section through the mid-dorsal region of a larva of 

 P. rapae, taken just back of the head, in the place where the cuticula 

 splits when moults occur. 



Fig. 10. — Portion of a cross section (i.e., perpendicular to the trend of the nervures) 

 through the pupal wing of A. archippus, about six days before 

 emergence. 



Fig. 11. — View looking down upon the upper (i.e., exposed) surface of one of the 

 large scales situated upon the nervures of A. archippus. Stage, 

 about four days before emergence. 



Fig. 11a. — Leucocyte found within the srjale represented by fig. 11, about four days 

 before emergence. 



Fig. 12. — Portion of a longitudinal section through one wall only of the pupal 

 wing of E. antiopa, slightly more developed than fig. 5. 



Fig. 13. — Portion of a longitudinal section (i.e., parallel with the trend of the 

 nervures) through the pupal wing of Anosia archippus, about eight or 

 nine days before emergence. 



ABREVIATIONS USED IN PLATE I. 



cl.frm. 



elm. 



rta 



anterior. 



formative cells of the scales. 



chitinous pillars found in 



scales. 

 outer chitinous cuticula of 



the larva, 

 outer chitinous cuticula of 



the pupa, 

 inner cuticula membrane of 



pupa, 

 wing membrane. 

 fbr. Wclrm. hypodermal fibres of pupal 



wings, 

 hypodermis. 

 leucocytes. 

 vacuolated leucocytes, as 



found in the very young 



pupa. 



eta,' 



eta". 



eta., al. 



h'drm. 

 leu'ey. 

 leu'ey' . 



leu'' 



->/'■ 



elongated spindle-shaped 

 leucocytes. 



mbr 



. ba. 



basement membrane of the 

 larval hypodermis. 



mbr 



. m. 



middle membrane of the 

 larval wings. 



mbr 



. pr. 



Grundmembran of Semper. 



nl. 





nuclei of the stellate cells 

 that secrete the Grund- 

 membran. 



P- 





posterior. 



pre. 





processes of young hypo- 

 dermis cells. 



sq. 





scale. 



th. 





tubes produced from the 

 newly - formed Grund- 

 membran. 



tr. 





trachea. 



