A contribution to our knowledge of the Stylopidae. 269 
Fig. 9. Median longitudinal section through a slightly older egg 
than the one shown in Fig. 8. Lettering as in the other figures. 
Fig. 10. Median longitudinal section throug an egg where se- 
condary yolk is beginning to form. sc.yk secondary yolk. pr.yk pri- 
mary or original yolk. Other lettering as in the other figures. 
Prate23! 
Fig. 11. Median longitudinal section through an egg in which 
the germ band has attained its full size and most symmetrical arrange- 
ment of cells. 
Fig. 12. A later stage of the germ band. Vitellophags (vt) can 
now be seen in the yolk. 
Fig. 13. Section of a small portion of an egg at the time of 
cleavage, showing its arrangement in the fat body. yk egg yolk. 
Fc fat cells. Fo.C degenerating cells remaining from the ovarian 
tubule. Ch Chorion. 
Fig. 14. Section through an egg in the same stage as the one 
shown in Fig. 10. Stained in iron haematoxylin and orange G to 
show the primary and secondary yolk. Emb embryo. Pr.Yk primary 
yolk. Sc.Yk secondary yolk. 
Fig. 15. Section through an embryo in the abdominal region just 
before the closing of the neural tube. c the large extra-embryonic 
cell of unknown function. 
Fig. 16. Section through a portion of an egg just previous to the 
fusion of the female pronucleus and the second polar body. ®pr female 
pronucleus. s.pb second polar body. 
Fig. 17. Fusion of the female pronucleus and second polar body. 
Fig. 18. Section through an egg full of cleavage cells still con- 
nected by their protoplasmic threads (pr.t). c.c cleavage cells. p.p 
peripheral protoplasm. b.c a cleavage cell just reaching the peri- 
phery, now really a blastoderm cell. 
Fig. 19. Surface view of an embryo with well formed appendages, 
as it is oriented in the egg. a antenna. m mandible. /stmx, 2ndmx 
first and second maxillæ. ¢,¢,¢, thoracic legs. a,a,a;a, etc. ab- 
dominal appendages. Five vitellophags can be seen in the central mass 
of yolk. 
Fig. 20. Several isolated extra-embryonic cells. a) Seen edgewise, 
b) showing deeply staining granules in the cytoplasm, c) binucleate cell. 
Fig. 21. Embryo in same stage as the one in Fig. 19 but un- 
curled. This is necessarily a composite figure reconstructed from nu- 
merous embryos. Lettering as in Fig. 19. 
Fig. 22. A female larva at the end of the first legless instar. 
m mouth. p pharynx. 06 brain. e.s eye spot. ¢.m asymmetrical 
thoracic muscles. 7 intestine. e eggs. o oviduct. v vagina. 
18* 
