PLATE 6 



EXPLAXATION OF FIGURES 



77 Polar view of spermatogonia! metaphase of Hesperotettixspeciosus. There 

 are twenty-one rod-shaped chromosomes and a V with unequal arms. The sub- 

 sequent history shows this to be a multiple chromosome consisting of the accessory 

 chromosome and one euchromosome. While of the same shape as the chromo- 

 somes of Stenobothrus which have subterminal attachment it is of different com- 

 position. 



78 Lateral view of a first spermatocyte metaphase complex of Hesperotettix 

 speciosus, the multiple chromosome at the right with the accessory chromosome 

 portion marked A'. 



79 Two multiple chromosomes from Hesperotettix speciosus. 



80 Two multiple chromosomes from Hesperotettix viridis. 



81 Two multii)le chromosomes from Hesperotettix pratensis. 



82 A multiple chromosome of Mermiria in prophase, the tetrad portion gran- 

 ular, the accessory chromosome homogeneous. 



83 An oblique view of a first spermatocyte metaphase complex of Hesperotet- 

 tix pratensis showing the eleven separate chromosomes with the accessory chromo- 

 some attached to one of the tetrads. 



84 Multiple chromosomes in prophase, at o and b of Hesperotettix speciosus, 

 at c of Mermiria. The accessory chromosome. A', is homogeneous and does not 

 show its longitudinal cleft, while the tetrads are granular and cleft. 



85 Polar view of second spermatocyte metaphase of Boopedon nubilum, in- 

 cluding accessory chromosome. 



86 Polar view of first spermatocyte metaphase of Boopedon, complete 

 complex. 



87 Lateral view of first spermatocyte metaphase spindle of Hesjierotettix 

 pratensis, the multiple chromosome in black. 



88 to 91 Successive stages in the concentration and division of an unequal 

 tetrad of Phrynotettix magnus. The shorter member, at the left in each figure, 

 remains granular until complete separation in the metaphase. It is apparent 

 that this is an equation division of each univalent part of the tetrad (see figs. 125 

 and 126 for photomicrographs of chromosomes drawn in fig. 88). 



92 and 93 Polar views of first spermatocyte metaphase of Mestobregma plattei, 

 showing variation in number of rings. 



94 to 98 From Chortophaga viridifasciata. 



94 and 98 Polar views of spermatogonial metaphases ; in the former there are 

 four tetrads, in the latter all the elements are separate. 



95 Polar view of second spermatocyte metaphase of Chortophaga containing 

 the accessory chromosome. 



96 and 97 Lateral views of first spermatocyte metaphase complexes arranged 

 in order of the sizes of their members. The variation in the form of the chromo- 

 somes with the stage of division shown. Chromosome 12 of figure 97 is a lateral 

 view of a ring in which the contrasynaptic ends are extended like the synaptic. 



740 



