Page:Popular Science Monthly Volume 71.djvu/217

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AGE, GROWTH AND DEATH

PSM V71 D217 Ten stages of the developing chick by franz keibel.png

Fig. 35. Ten Stages of the Developing Chick, after Franz Keibel. All the figures are magnified four diameters. In No. 1 only the parts indicated in the vertical axis of the figure correspond to embryonic structures proper.

 
No. 1. Incubated 20 hrs. No. 6. Incubated 3 days, 16 hrs.
No. 2. " 24 hrs. No. 7. " 4 days, 8 hrs.
No. 3. " 2 days. No. 8. " 5 days, 1 hr.
No. 4. " 2 days, 19 hrs. No. 9. " 7 days, 4 hrs.
No. 5. " 2 days, 22 hrs. No. 10. " 8 days, 1 hr.

a series of pictures to illustrate in the same manner the progressive development of the rabbit. Numbers one to five of the figures upon the screen represent what is known as the germinal area, in the center