PLATE 3 



EXPLANATION OF FIGURES 



Small numerals in figures 1, 4, 5, and 6 correspond to the numbers of the 

 chromosomes in plate 1. The small numerals in figures 22 and 23 correspond to 

 the numbers of the chromosomes in plate 2. c, indicates the chromomere ves- 

 icles; X, indicates the accessory chromosome. 



1 to 11 From the same smear of Chorthippus that was used for the drawings 

 on plate 1. Figures 12 to 14 are from sections of another individual of the same 

 species. 



1 to 4 Zygotene stages, showing partially conjugated threads. In figures 

 2 to 4 the apices of the atelomitic chromosome no. 9 are marked by chromomere- 

 vesicles (c). 



5 Pachytene stage. Chromomere-vesicles (c) partially fused. 



7 and 8 Telophases of spermatogonia showing chromomere-vesicles (c) at- 

 tached to chromosomes no. 9. Chromosome vesicle of accessory at A'. 



9 to 11 Tetrads of chromosome 9, illustrating variation in chromatid arrange- 

 ments at about the same stage. 



12 to 14 Tetrads of no. 9 from sections showing chromomere-vesicles and 

 variety of chromatid arrangement. 



15 to 23 Trimerotropis; from same smear as that used for drawings in plate 2. 



15, 17, .and 19 Prophase tetrads which may be considered forerunners of the 

 metaphase figures 16, 18, and 20, respectively. 



21. Zygotene stage showing partially conjugated threads. 



22 and 23 Late pachytene stages showing chromomere-vesicles on chromo- 

 somes no. 4, and no. 8. 



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