Figure 2

Proembryoid II and III. A, B, D: Lateral views; live specimens immersed in mineral oil; C: unfixed preparation mounted on a slide and viewed at the compound microscope with Nomarski optics. A: the proembryoid III has partially shed the II exuvia (e2) while the embryonic cuticle (ec) and the chorion (c) are still attached at the rear end of the animal and the proembryoid I exuvia (e1) still covers part of the trunk, overlying the e2 exuvia. In B the chorion and embryonic cuticle, and in B1 also the proembryoid I and II exuviae (e1, e2) have been removed to show all limb buds (lb) of the proembryoid III stage. The limb buds of the last LBS is now visible (arrowhead); note that the specimen in B is slightly younger than the one in A, with the e2 exuvia still covering most of the trunk. B2: high magnification of B, showing the extent of differentiation of the most anterior limbs including the antenna (a), second maxilla (mx2), maxilliped (mxp), first leg (lb1) and the tergite (t). C: high magnification of an antenna, showing the differentiation of all 14 antennomeres. D: high magnification of terminal part of the trunk, showing the initial development of the last limb bud (arrowhead). Scale bars: A, B, B1: 500 μm; B2, D: 200 μm; C: 100 μm.