George Lefevre and Caroline McGill 487 
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Fie. 4. Anax junius. <A, B, Second spermatocyte-division, showing undi- 
vided heterotropic passing to one pole and the m-chromosome dividing in 
A; C, D, later anaphases, second division, still showing undivided heter- 
otropic in advance of other chromosomes; H, F, anaphase groups from same 
spindle, polar view, second division, showing the m-chromosome and macro- 
chromosome in each and the heterotropic (h) in #; G, H, late anaphases, 
second division, showing the heterotropic lagging behind instead of advanc- 
ing in front of the other chromosomes. 
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"A B C D E 1m G H fl 
Fig. 5. Anax junius. Slightly schematic representation of successive 
stages in formation of tetrads and axial relations of same; A, longitudinally 
split bivalent from late growth-period; B, C, condensation of bivalents; 
D, formation of cross; £, cross with the four parts distinct, oriented on 
spindle with original long axis placed lengthwise; F’, condensation of tetrad; 
G, tetrad beginning to open; H, tetrad completely separated into 4 parts; 
I, divergence of the divided dyads in anaphase of first maturation mitosis. 
