PLATE 3 



EXPLANATION OF FIGURES 



32 to 68 From Mecostethus lineatus. 



32 to 34 Polar views of first spermatocyte metaphase complexes. All the 

 chromosomes are in the form of rods, straight or, more commonly, bent at the 

 synaptic ends into V-shaped figures. The entire absence of the common rings is 

 noteworthy in this species (see fig. 100 for photomicrograph of the cell drawn 

 in fig. 34). 



35 Beginning of the first spermatocyte anaphase. The chromosomes here 

 are all of the common V-shape, the same as in complexes with rings (cf. figs. 

 5-7). The only unusual behavior is the divergence of the limbs of the V's before 

 separation of daughter chromatids in the equatorial plate. 



36 Oblique view of three euchromosomes and the accessor}^ chromosome in 

 the first spermatocyte metaphase. 



37 Polar view of the first spermatocyte metaphase. 



38 Various metaphase chromosomes of first spermatocyte (except the lowest 

 chromosome which is late prophase). The character of the chromosomes at this 

 period is shown in the different views. 



39 Four first spermatocyte metaphase euchromosomes. The chromatids of 

 the two small euchromosomes remain in contact until the end of the metaphase 

 as in most other species. 



40 Oblique view of three euchromosomes in early anaphase. 



41 to 43 Polar views of first spermatocyte metaphase. Twelve is the haploid 

 number, but because of the early poleward movement of the accessory chromo- 

 some it does not often appear in the plate. One other chromosome is missing 

 from figure 37. 



44 Polar view of spermatogonial complex in metaphase. 



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