ECOLOGY AND BIOLOGY OF THE PACIFIC WALRUS 



205 



Fig. 122. Postpartum decrease in 

 length of the uterine horn of preg- 

 nancy and the suggested subse- 

 quent annual cycle of uterine 

 size. Curve was fitted visually. 



Years Since Parturition 



79 



■t 



9— -3.21 



M 



J \ I I I I I I I \ \ L-L 



.2 .4 .6 .8 1.0 2.0 4.0 

 Years Postpartum 



10.0 20.0 



Fig. 123. Postpartum diminution in diameter of the corpus albicans of pregnancy. 

 Bars show range and mean of samples greater than one; sample size is indicated above 

 each bar; x, single specimens. Samples of Atlantic walruses (Mansfield 1958a) are 

 distinguished from those of Pacific walruses by M, beneath the bar. Visually fitted curves 

 indicate the estimated mean (solid) and extremes (dashed). 



