Wing, wing-scales, and their pigments in butterflies and moths. 135 



hfemolymph (blood), within the wings, is under considerable pressure, 

 and this would tend to enlarge the wing into an inflated bag ; but the 

 hypoderraal fibres (PI. iii., fig. 8), before described, hold the upper 

 and lower walls of the wings together, and the bag becomes a fiat, 

 instead of an inflated, one. In A. archippm, Mayer points out that 

 " the area of the wing of the imago is 8-6 times that of the pupa, ihe 

 wing of the newly-formed pupa has about 60 times the area of the 

 \v[n<r in the mature larva, so that it is evident that, m passing from 

 the larval state to maturity, the area of the wings increases more than 

 five hundred times." 



(To be continued). 



DESCRIPTION OF PLATE III. 



Fi- l.-Loncritudinal section through the left hind-wing of the 

 mature larva of Pleris rapae. The plane of the section 

 is parallel to the frontal plane of the larva, i.e., perpen- 

 dicular to its dorso-ventral axis. 



Fio- 2 —A portion of a cross-section of the larval wmg of P. rapae. 



Fio' 3— Longitudinal section {i.e., with the trend of the nervures) 

 through the pupal wings of Samia cecropia. ihe sec- 

 tion is taken near the lower free edges of the pupal 



wing cases. i i.- i„ 



Ficr i —Portion of a longitudinal section through the pupa cuticula 



°' ■ and wing tissue of S. cecropia. Specimen killed m 



January. 



Ki^ 5 —Portion of a longitudinal section through one ot the young 



puiml wings of a chrysalis of Eucanesm antiopa. 

 Ki„ 6 -Portion of a longitudinal section through a pupal wing ot 



°" ■ Anoua archippm, about eight days before emergence. 



FicT 7 —Portion of a longitudinal section through one of the pupal 

 "■ ■ wino-s of A. archippm, about eight days before emergence 



Fio- 8 -Portion" of a longitudinal section through a pupal wmg ot 



°' ' A. archippm, about five days before emergence. 



Fio- 9 —Portion of a cross section through the mid-dors^il region ot 

 °" ■ a larva of P. rapae, taken just back ot the head, m the 



place where the cuticula splits when moults occur. 

 Fi. 10— Portion of a cross section (i..'., perpendicular to the trend 

 "■ ■ of the nervures) through the pupal wmg of A. archippm, 



about six days before emergence. 



11 _View looking down upon the upper {i.e., exposed) surface of 

 one of the large scales situated upon the nervures of 

 A. archipims. Stage, about four days before emergence. 



11a.— Leucocyte found within the scale represented by fag. 11, 

 about four days before emergence. „ i * 



12 -Portion of a longitudinal section through one wall only o 

 the pupal whig of E. antiopa, slightly more developed 



Fi-. 13.-PortioT ot^ a'' longitudinal section (/..., parallel with the 

 trend of the nervures) through the pupal wmg ot Awma 

 archippm, about eight or nine days before emergence. 



Fit 



Fio- 



