SOMATIC MITOSIS AND CHROMOSOME INDIVIDUALITY 161 



D 



FIG. 56. The chromosome complement of Vicia faba. 



A, B, two successive sections of a mitotic figure in the root tip, showing together the 

 12 split chromosomes, 2 of them about twice as long as the other 10. C, cross section of 

 the group of chromosomes at anaphase: each of the long chromosomes, being drawn pole- 

 wards by the middle, shows both ends, making the number apparently 14. D, E, two 

 successive sections of a heterotypic figure in the microsporocyte, showing the 6 bivalents; 

 the large one is at the left. F, polar view of heterotypic mitosis at metaphase, showing the 

 6 bivalents. X 1400. (Original.) 



FIG. 56 bis. 



A, anaphase of somatic mitosis in Crepis virens, showing 2 long, 2 medium sized, and 2 

 short chromosomes passing to each pole. (After Rosenberg, 1920.) B, the chromosome 

 complement in a somatic cell of Najas major, showing the 7 homologous pairs. (After 

 Tschernoyarow, 1914.) 



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