32 



Mary Blount. 



.*.'•::.•; 



Fig. 14. — Posterior side of a longitucliual section of a pigeon's egg about 

 twenty-five liours after fertilization, 8.50 p. m. 1. Nests of periblast nuclei. 

 2. Periblast nucleus. 3. Syncytial mass derived from the periblast, organizing 

 into cells w^hicli will be added to the blastodisc. 4. Vacuoles. 







!•• • -j'^ r ft-'*- 



Fig. 14a. — From the section as shown in Fig. 14. vm., vitelline mem- 

 brane, pv., perivitelline fluid, y, yolk granules in the marginal periblast, 

 n, the nuclear nest numbered 1 and nearest to the cleavage in Fig. 14. Leitz 

 4/t'2- Tube length 140 mm. 



