278 GERM-CELL CYCLE IN ANIMALS 
Fie. 76.— Mitochondria in the embryonic cells of the chick. A. In 
cells of the primitive streak. B. In dividing connective tissue cells. 
C. In connective tissue cells. D. In a cartilage cell. 2. In osteo- 
blasts and bone cells. F. In cells of Wolffian body. (From Dues- 
berg, 1913; A, B, C, E, after Meves; D, F, after Duesberg.) 
