463 
ADAM SEDGWICK. 
Fig. 33. Ventral view of head and segments of jaws and oral papillae of 
young embryo of same stage (E). Brain ungrooved. Ectoderm of 
sides of mouth beginning to grow inwards (s^.). Oral papillae perforated. 
Opening of salivary glands ( o . s.) at base of oral papillae, j. Jaw. 
L. Lips (buccal fold). M. Mouth, o. s. Opening of salivary gland. 
p. s. praeoral somite, st. Ectodermal ingrowth at sides of posterior 
part of mouth to form stomodaeum. 
Fig. 34. Same view of slightly older embryo, with sides of mouth quite 
infolded (st.) and a new posterior border to the mouth formed. Brain 
still ungrooved. References as in Fig. 33. 
Fig. 35. — Ventral view of head of embryo intermediate between Stages E 
and F. Grooves in brain wide and shallow. The lips have grown considerably 
and have extended behind the openings of the salivary glands, but have not 
yet joined in the middle line. At. Antennae, c. g. Groove in brain, j. Jaws. 
j. s. Swelling at base of jaws. L. Lips. M. Mouth, or.p. Oral papillae 
o. s. Opening of salivary glands. 
Fig. 36. — Stage F. Groove in brain almost closed ; the opening is slightly 
wider anteriorly. Lips complete and folded, salivary opening quite covered by 
them. Jaws completely enclosed. Swelliugs at base of jaws closely approxi- 
mated so as to reduce the mouth opening to a narrow sb’t. The praeoral lobes 
have completely united with one another (cf. Figs. 33 — 35). References as 
in Fig. 35. 
Figs. 37 and 3S. — Stage G-. 
Fig. 37. Side view of embryo of Stage G. Full number of legs and oral 
papillae. Length 5 — 6 mm. An. p. Anal papillae. At. Antennae. 
d. Dorsal ectodermal thickening. F. 1 — 17. The legs. me. Mesen- 
teron. or.p. Oral papillae. R. Rectum, s. g. Salivary glands, s. o. 
4 and 5. Segmental orgaus of 4th and 5th legs. si. g. Slime glands. 
Fig. 38. Embryo of Stage G, curled up as in the uterus. 
