Crayfish testis was fixed in Bouin''s soln., embedded in paraffin and sectioned at 0.5jn. The metaphase spindle of the maturation division in the crayfish testis seems to be composed largely of longitudinally oriented "chromosomal fibers" measuring about 1500-2500 A in width. These fibers appear to be compound, i.e., made up of smaller fibers of about 300-600 A in width. Both the "chromosomal fibers" and their smaller fibrous components may at times show banding, which is possibly the result of irregular contraction during fixation. The centrioles appear relatively dense, are irregular in outline, and are probably not homogeneous bodies. The "chromosomal fibers" and astral rays lose their usual orientation at the periphery of the centriole. "Interzonal fibers" are relatively small in the late anaphase stages of the crayfish testis.