PLATE 61 



Crepis taraxacifolia X tcctorum, F,. 



Fig. 46. Homotypic anaphase witli four chromosomes in all four groups. 

 Fig. 47. Homotypic anaphase with 3/2/3 chromosomes in the upper of the 

 two division figures and 4/1/3 in the lower one. 



Fig. 48. Represents the tetrad that probably would result from the division 

 shown in figure 47, the figures in the nuclei giving the number of chromosomes in 

 the four nuclei and three micronuclei. 



Fig. 49. A nonad of which three nuclei probably have three chromosomes each, 

 one prol)ably has two chromosomes, and five are micronuclei with probably only 

 one chromosome each, giving the total of sixteen chromosomes in the nine nuclei. 



Figs. 50-51. Tetrads with micronuclei; in figure 51 one of the cells is very 

 small. 



Fig. 52. A true diad. 



Figs. 53 and 54. Triads; in figure 54 one of the cells has two nuclei. 



Crepis aspera X aculeata Fj. 



Iron-acetoearmine smears. The material previously fixed in Carnoy. 



Figs. 55-56. Heterotypic metaphase; in figure 55 4j, (the most common case), 

 in figure 56 3n + 2j. 



Fig. 57. Heterotypic anaphase; one chromosome lagging and splitting. 



Fig. 58. Tetrad; one of the few cases where micronuclei were found. 



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