Figure 17.

Stages 35 and 36: Anterior–posterior axis reads left to right in both images. Scale bar = 1 mm. Stage 35 (7 ½ days). Stage 36 (7 ¾ days). Abbreviations: al, alula; cf, choroid fissure; el, eyelid; er, opening to ear; et, egg tooth; fg, feather germ; fl, forelimb; hal, hallux; hl, hindlimb; ica, internal carotid artery; le, lens vesicle; md, mandibular process; ms, mesencephalon; mx, maxillary process; na, nail; nar, nares; ot, otic vesicle; pr, pigmented retina of eye; tb, tailbud; tbt, tibiotarsus; te, telencephalon; tl, tail; tmt, tarsometatarsus; v1, lateral ventricle of telencephalon. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]