476 BOTANICAL GAZETTE [june 



Fig. 27. — Third contraction complete; libers have completely filled the 

 nuclear cavity. 



Fig. 28. — Multipolar spindle; chromosome aggregation loosening up. 



Fig. 20. — Formation of the individual wefts of fibers for each chromosome; 

 the scattering of the bivalents upon the fibers; and a step farther in the transi- 

 tion from multipolar to bipolar spindle. 



FlG. 30. — A later stage. 



plate xxx 



Fig. 31. — Bipolar spindle; bivalents stretched out upon the fibers. 



Fig. 32. — Polar view of early metaphase. 



FlG. 33.— Polar view of metaphase with bivalents peripherally arranged. 



Fig. 34. — Metaphase in which the individual wefts of fibers are extending 

 from each chromosome to the pole; also the fibers' massive organization at the 

 point of attachment; to the left is a weft that has been broken from its chro- 

 mosome. 



Fig. 35. — Farly anaphase; the longitudinal halves of each somatic chro- 

 mosome that arose by vacuolation in early anaphase are again becoming 

 apparent. 



Fig. 36. — Anaphase ; halves of the somatic chromosomes entirely separated. 



Fig. 37. — Polar view of the same. 



Fig. 38. — Late anaphase; 16 half chromosomes approximating end to end 

 to form a spirem 2.v chromosomes in length. 



Fig. 30. — Daughter nucleus after loosening up of chromosomes. 



FlG. 40. — Daughter nucleus; irregular net appearance due to the anas- 

 tomoses. 



Fig. 41. — Daughter nucleus; spirem stage in which the fibers of previous 

 mitosis have not disappeared. 



Fig. 42. — Daughter nucleus; late spirem in which the outlines of the 

 segments are discernible. 



Fig. 43. — A later stage in which the multipolar complex has appeared. 



Fig. 44. — Segmentation into 16 segments followed immediately by their 

 pairing. 



Fig. 45. — rolar view of metaphase .of homotypic mitosis. 



Fig. 46. — Late metaphase of the two daughter nuclei. 



Fig. 47. — Same, but only one daughter nucleus in plane. 



Fig. 4S. — Anaphase of homotypic mitosis. 



Fig. 49. — Telophase of homotypic mitosis; end to end approximation of 

 8 chromosomes just previous to organization of granddaughter nucleus. 



