*77:20-23 According to Langman's Medical Embryology, by T. W. Sadler (Fifth Edition, Page 88): ``In general the length of pregnancy for a full term fetus is 266 days or 38 weeks after fertilization.'' Both 266 and 38 are multiples of 19 (Appendix 1).

*77:20-23 According to Langman's Medical Embryology, by T. W. Sadler (Fifth Edition, Page 88): "In general, the length of pregnancy for a full term fetus is 266 days or 38 weeks after fertilization." Both 266 and 38 are multiples of 19 (Appendix 1).