736 



SPERM, OVA, AND PREGNANCY 



mm/mm. 

 2.0 



1.5 



1.0 



0.5 



mg. 

 500 



400 



300 



200 



7 

 14 



12 



10 



8 



37.1 

 37.0 

 36.9 

 36.8 

 36.7 



SPERM PENETRATION 



DRY CONTENT OF MUCUS 



BASAL TEMPERATURE 



98.8 

 98.6 

 98.4 

 98.2 

 98.0 



12 16 



DAY OF CYCLE 



20 



24 



28 



Fig. 13.9. Variation in human sperm penetration in vitro through cervical mucus during a 

 single cycle (from J. K. Lamar, in Problems oj Human Fertility, George Banta Publishing 

 Company, 1943), correlated with cyclical changes in the mucus and in body temperature 

 based on 35 cycles (from P. Bergman, Acta obst. et gjmec. scandinav., Suppl. 4, 29, 1-139, 

 1950). 



scriptive and experimental investigations 

 have pointed out the complexity of the junc- 

 tion and the high pressures often required 

 to force an opening through the lumen in this 

 region. Rubin's initial paper (1920) indi- 

 cated that gas pressures of 40 to 100 mm. Hg 

 could be considered a normal range for hu- 

 man tubal insufflation, the uterotubal junc- 

 tion being the major source of resistance. In 



the cat, fluid pressures of 250 to 300 mm. Hg 

 are incapable of "forcing" the opening when 

 injections are made through the uterus (Lee, 

 1925a; Anderson, 1928). On the other hand, 

 tubo-uterine injections of fluid, that is, those 

 from tube to uterus, recjuire very little pres- 

 sure to force the opening. Other species be- 

 have differently. With relatively little pres- 

 sure, between 25 and 40 mm. Hg, fluid can 



