Altered spermatozoa of Chimaericola leptogaster in caeca and genito-intestinal canal. A, B, transverse sections of altered spermatozoa in caecum, showing swollen cytoplasm and swollen mitochondrion without crests. C, a typical unaltered spermatozoon section in caecum, probably corresponding to a spermatozoon just transferred to this organ. D, E, transverse sections of altered spermatozoa in genito-intestinal canal. Scale in A, valid for A, C, D, E. All scales: 500 nm.