title: Observations on the fine structure of the nuclear ring of the mammalian spermatid.
mesh_terms: D000818:Animals; D002462:Cell Membrane; D002467:Cell Nucleus; D006224:Cricetinae; D006168:Guinea Pigs; D006652:Histological Techniques; D008297:Male; D051379:Mice; D008854:Microscopy, Electron; D008870:Microtubules; D008961:Models, Structural; D012377:Rodentia; D012589:Sciuridae; D012788:Shrews; D013045:Species Specificity; D013094:Spermatozoa / Q000166:cytology*