PLATE 2 



EXPLANATION OF FIGURES 



5 Section through specimen 276 to show the position and detail of germ 

 cells in the area indicated in figure 5a. 



6 Detailed study of a section through the posterior third of a seven somite 

 embryo showing germ cells in the gut entoderm. The condition in the three 

 somite stage is similar. 



7 Section through the primitive intestine of specimen 449 (10 somite stage) 

 depicting the position of the germ cells, and the comparative size of germ cells 

 and erythrocytes. Refer to figure 7a for orientation. 



8 Section through the gut region of specimen 365 (14 somite stage) showing 

 the amoeboid shape of the germ cells at this time. The rectangle in figure So 

 roughly indicates the area from which the drawing was made. 



360 



