488 
J. BRONTE GATENBY. 
Fig. 9. — Oblique section of a sperm bundle of S. populi, showing 
normal acrosome formed near lagging nuclei, all of which have fallen 
away. Macromitosome normal. 
Fig. 12. — Spermatozoon of S. populi, showing abnormal formation 
of macromitosome. From C. to Y. is normal. The part M. contains 
the main part of the mitochondrial matter, while at Z. there has been 
an attempt at elongation. 
Fig. 13. — Spermatid with four nuclei, all of which stain as they 
do in normal stages. Cell otherwise normal, but each nucleus has a 
granule, which may or may not be derived from acrosomic matter. 
S. populi. 
Fig. 14. — ’Spermatid of Pygaera bucephala, showing fairly normal 
macromitosome, but quite degenerate nucleus (October). 
Fig. 15. — Mid part of bundle of metamorphosing spermatozoa of 
Pieris, showing abnormal acrosome not properly fused to the nucleus. 
