AN EXTRA DYAD AND EXTRA TETRAD IN CAMNULA 423 
Although the camnulan supernumerary may be present in 
varying combinations in different follicles of a gonad, it seems 
nevertheless to reproduce itself regularly at mitosis and to main- 
tain its identity throughout the spermatogonial and spermato- 
cyte generations. Since we can observe, too, most of the steps 
in the formation of some of its combinations, from the first sper- 
matocyte metaphase to the second spermatocyte telophase, it 
offers evidence for, rather than against, the doctrine of the 
genetic continuity of the chromosomes. 
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