ITS DIFFERENT PHASES OF DEVELOPMENT IN THE ANIMAL SERIES. 85 
Fig\ 1 b. The same cell after the action of acetic acid. The granules have been dis- 
solved and a cellseform nucleus exposed. 
Fig. 2 a. Granule-cell in finely granular stage, after having collapsed and shot out 
processes. 
Fig. 2 b. The same, distended by water. 
Fig. 2 c. The same, after the action of acetic acid. If the acid has been very much 
diluted, and applied only after the distention of the cell by water, the ap- 
pearance of the single large cellseform nucleus is produced ; in the contrary 
case, the appearance of several small ones. 
Second Phase. — Nucleated Cell. 
Fig. 2 d. Cell in transition from granule to nucleated phase. 
Fig. 3. Nucleated cell, uncoloured stage. The very pale cell- wall is seen on one side 
only of the very distinct nucleus. 
Figs. 4 and 5. Nucleated cells, uncoloured stage, the one circular and the other oval. 
Fig. 6. Nucleated cell, coloured stage, or the well-known oval “red corpuscle.” 
Common Fowl. 
It has not been thought necessary particularly to describe the blood-corpuscles of 
the Bird. These few figures of the blood-corpuscle of the Common Fowl have been 
given merely for the sake of reference and comparison. 
First Phase . — Granule-cell. 
Fig. 1 . Granule-cell, coarsely granular stage. 
Fig. 2. Granule-cell, finely granular stage. 
Second Phase. — Nucleated Cell. 
Fig. 3. Nucleated cell, uncoloured stage. 
Fig. 4 a. Nucleated cell, coloured stage, but still circular. 
Fig. 4 b. The same cell, with the nucleus brought into view by the action of acetic 
acid. 
Fig. 5. Nucleated cell, coloured stage, oval. 
Mammiferous Embryo — Ox, \\ inch long. 
First Phase . — Granule-cell. 
Fig. 1 . Granule-cell, coarsely granular stage. 
Fig. 2. Granule-cell in transition from coarsely granular to 
Fig. 3. Finely granular stage. This cell, in which the cellseform nucleus is already 
visible through the finely granular contents, may be viewed as a trans- 
ition to the phase of nucleated cell. 
