The works of Francis Maitland Balfour, Volume 1 (of 4)

by Francis M. Balfour

5. H. Ludwig, “Ueb. d. Bildung des Blastoderm bei d. Spinnen,” Zeit. f. wiss. Zool., Vol. XXVI. 1876.

EXPLANATION OF PLATES 30, 31, AND 32.

Plate 30.

Complete List of Reference Letters.

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.