SPERMATOGENESIS OF SILKWORM. 



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All the figures were drawn with the camera at the level of table and with Zeiss 

 apochromat 1.5mm. oil immersion objective and No. 18 compensating eye-piece, which 

 combination gives an enlargement cf 48CO diameters. — Fig. I, metaphase of spermatogonial 

 division in the domesticated silkworm (" Shirojima " x" Kurojima ") ; polar view. — Figs. 2 

 and 3, equatorial plates of first sperm atocyte-division in the wild silkworm (27 chromo- 

 somes). — Fig. 4, second spermatccyte-division in same (27 chromosomes). — Fig. 5, first division 

 in the domesticated silkworm, race " Italian No. 1 " (28 chromosomes). — Fig. 6, same, race 

 " Kasasagi." — Fig. 7, second division in same, race '• Birödo." — Fig. 8, same, race " Kasa- 

 sagi " ; side view. 



