The works of Francis Maitland Balfour, Volume 4 (of 4)

by Francis M. Balfour

ch. Cheliceræ. ch.g. Ganglion of cheliceræ. c.l. Caudal lobe. p.c. Primitive cumulus. pd. Pedipalpi. pr.l. Præoral lobe. pp¹. pp². etc. Provisional appendages. sp. Spinnerets. st. Stomodæum.

I-IV. Ambulatory appendages. 1-16. Postoral segments.

Fig. 1. Ovum, with primitive cumulus and streak proceeding from it.

Fig. 2. Somewhat later stage, in which the primitive cumulus is still visible. Near the opposite end of the blastoderm is a white area, which is probably the rudiment of the procephalic lobe.

Fig. 3a and 3b. View of an embryo from the ventral surface and from the side when six segments have become established.

Fig. 4. View of an embryo, ideally unrolled, when the first rudiments of the appendages become visible.

Fig. 5. Embryo ideally unrolled at the stage when all the appendages have become established.

Fig. 6. Somewhat older stage, when the limbs begin to be jointed. Viewed from the side.

Fig. 7. Later stage, viewed from the side.

Fig. 7a. Same embryo as fig. 7, ideally unrolled.