478 TREA D WELL . 



DESCRIPTION OF PLATES. 



In the following drawings no attempt has been made to represent the actual 

 appearance of the cells, but only to indicate their size and position and the direc- 

 tion of the karyokinetic spindles. A peculiar feature of Podarke is the large size 

 of the nuclei with their prominent chromosomes, the latter being especially promi- 

 nent after staining with haematoxylin. These characters are not exaggerated in 

 the drawings. 



EXPLANATION OF PLATE XXXVL 



Fig. I. First cleavage spindle, p^, polar globules. 



Fig. 2. Two-cell stage- from above. 



Fig. 3. Four-cell stage from above. 



Fig. 4. Eight-cell stage from the side. 



Fig. 5. Eight-cell stage from above. 



Fig. 6. Eight, forming sixteen cells. Formation of second quartette. 



Fig. 7. Sixteen cells from the side. 



Fig. 8. Sixteen, forming twenty-four cells. Formation of third quartette and 

 intermediate cells. 



Fig. 9. First division of primary trochoblasts. 



Fig. 10. Twenty-eight to thirty-two cells. Division of second quartette. 



Fig. II. Thirty-two to forty cells from above. Formation of apical rosette. 



Fig. 12. Forty cells forming fifty-six. Second division of trochoblasts and 

 first division of intermediate cells. 



