TRANSACTIONS OF MICROSCOPICAL SOCIETY. 
EXPLANATION OF PLATES III. AND IV. 
N.B. — All the figures are drawn under the same magnifying power, 
save 2, 3, 4, and 9, which are much more highly amplified. 
Fig. 
1. (Plate III.) — One of the vitelline spheres or ova (there being then no 
perceptible difference between them) from a newly-formed capsule. 
2. — A small portion of the vitelline substance highly magnified. 
3. — Vesicula directrix, apparently single. 
4. — Vesicula directrix, double. 
6. — Segmentation of vitelline spheres ; a, h, c, d, e, successive stages. 
6. — Segmentation of vitellus of true ova ; a, h, c, successive stages. 
7. (Plate IV.) — Mass of vitelline segments beginning to coalesce, but 
torn apart so as to show an embryo, a, in the interior ; on either 
side are embryos in various stages of development, found in the 
same capsule, but not imbedded in the conglomerate mass. 
8. (Plate III.) — Early stages of development of embryo, up to the forma- 
tion of the mouth and cesophagus. 
9. — Ciliated mouth, as seen laterally at a, and from above at b. 
10. — Conglomerate vitellus, with attached embryos drawing-in its com- 
ponent particles. 
11. (Plate IV.) — Portion of a similar mass, with embryos, a, h, c, d, 
attached, aud others, e,f, detached, from the same capsule, of very 
different sizes. 
12. — Embryo having its transparent peripheral membrane speckled by 
small adherent particles, resembling the vitelline particles in fig. 2. 
This appearance is not at all uncommon. 
13. — Three embryos, a, h, c, of larger size ; their ciliated lobes obliterated 
by distention. 
14. — An embryo of unusually large size, with portion of conglomerate 
vitellus still adherent. 
15. 16. — More advanced embryo, with ciliated lobes and foot full}^ deve- 
loped, and the newlj^-appropriated vitellus in process of conversion 
into other organs. 
17. — A small embryo, which has apparently only just began to ingest 
its supplemental vitellus ; this being superposed upon the original 
yolk-mass. 
