title: Sperm penetration through zona pellucida and perivitelline space in the hamster.
mesh_terms: D000818:Animals; D006224:Cricetinae; D005260:Female; D005306:Fertilization; D066298:In Vitro Techniques; D008297:Male; D008722:Methods; D010057:Oviducts; D010063:Ovum / Q000166:cytology*; D013094:Spermatozoa; D013997:Time Factors