ITS DIFFERENT PHASES OF DEVELOPMENT IN THE ANIMAL SERIES. 101 
Second Phase. 
Fig. 9. Nucleated cell as seen when the blood is examined immediately on being 
drawn. 
Fig. 10. The same, changed in shape, as it appeared soon after the blood is drawn. 
Figs. 11 and 12. Nucleated cells distended by water. 
Blood vomited hy Medicinal Leech . 
Figs. 13 and 14. Granule-cells, coarsely and finely granular stages. 
Fig. 15. A transition cell. 
Figs. 16, 17 and 18. Nucleated cells. 
MOLLUSCA. 
Gasteropoda. — Whelk. 
First Phase. 
Fig. 1. Granule-cell, with the cell-wall shot out into processes. 
Fig. 2. The same, distended by water. 
Fig. 3. The contents and nucleus of the same, set free by the bursting of the cell- 
wall. 
Second Phase. 
Fig. 4. Nucleated cell, with the cell-wall shot out into processes. 
Fig. 4 a. The same, distended by water. 
Figs. 5, 6 and 7- Nucleated cells, the cell-wall of which did not shoot out into pro- 
cesses. 
Acephala. — Mussel. 
First Phase. 
Figs. 1 and 2. Granule-cells, coarsely and finely granular stages, with the cell-wall 
shot out into processes. 
Fig. 3. Granule cell after the action of water. 
Figs. 4 and 5. Granule-cells from a mussel which had been kept some time in the 
house. 
Second Phase. 
Figs. 6 and 7- Cells from the blood of fresh mussels, by the action of water on which 
a nucleus has been rendered visible, as in fig. 8. 
Figs. 9, 10, 11, 12. Nucleated cells found in considerable number in the blood of 
mussels kept some time, but few in number in fresh mussels. 
