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Explanation cf Plate III 



All figures were drawn with the aid of a camera lucida, and with a Zeiss' 

 apochromatic objective 2 mm and a comps. ocular 12 (xl5). Afterward all the 

 :figures were reduced 9/10. 



Fig. 1. A somatic cell showing 32 chromosomes. 

 Fig. 2. A pollen mother cell in synapsis stage, showing the extrusions of the 



nuclear substance. 

 Fig. 3. A pollen mother cell in synapsis stage. 

 Fig. 4. Early spirem stage. 

 Fig. 5. Later spirem stage. 



Fig. 6. Still later stage, when 32 chromosomes are formed. 

 Fig. 7. Second contraction. 



Fig. 8. Diakinesis. The bivalent and \inivalent chromosomes are seen. 

 Fig. 9. The metaphase of the bivalent chromosomes. The univalent chromosomes 



are scattering in the cytoplasm. 

 Fig. 10. The polar view of equatorial plate of the bivalent chromosomes, one longer 



isolated chromosome is a univalent chromosome. 

 Fig. 11. Later anaphase of the first division, showing both daughter chromosome 



groups having different chromosome numbers. 

 Fig. 12. Seven bivalent chromosomes are in later anaphase, but remaining four are 



in metaphase, and the univalent chromosomes are approaching to the 



equator. 

 Fig. 13. The equatorial plate of the univalent chromosomes. 

 Fig. 14. Interkinesis, normal. 



