410 FRANK E. LILLIE 



trace of the scrotum which is well developed in males of corre- 

 sponding size is to be found. In other words the derivatives of 

 the urinogenital ridge (gonads, Wolffian and Miillerian ducts and 

 ligaments) tend to develop in the male direction, but other 

 parts of the urinogenital system of such affected females are less 

 involved. 



In later stages the conditions established at the beginning 

 undergo farther development. Drawings of various stages from 

 21.5 to 28 cm. are shown in figures 20 to 27, and these will 

 hardly require detailed description after what has gone before. 

 A rather common anomaly is the evagination of the right gu- 

 bernaculum into the body cavity in place of growing into the 

 body-wall (figs. 20, 22, 25, and 27); it is difficult to assign a 

 cause for this; inasmuch as it rarely happens on the left side 

 (fig. 27) it is presumably associated with the asymmetry of the 

 urinogenital complex which is particularly striking in the case 

 of the kidneys (see all figures of dissections). The gonad re- 

 mains exceedingly small in these stages, nor is there much change 

 in other directions. Seixdnal vesicles, which occur frequently 

 at least in the sterile free-martins after birth are not yet found 

 though they are very evident in the male from 16.8 cm. on. 

 In the normal male the testes are drawn into the saccus vaginalis 

 at the 26 cm. stage (fig. 11); in the sterile free-martin this may 

 happen (fig. 25 A and B), or the gonads may remain in the 

 peritoneal cavity (fig. 26). 



History of cases: 



Figures 20 A and 20B. Case 2. Bovine twins. Male 23 

 cm., female 21.5 cm. Collected October 30, 1914. Chorion 

 single with constricted connection occupied by cotyledons be- 

 tween the two sides. This being one of the earliest cases no 

 record was made of vascular conditions in the chorion. No 

 record of maternal ovaries. 



Figure 21. Case 41. Bovine twins cf and <^ . Collected 

 February 16, 1916. Male 22.7 cm., female 21.8 cm. Both 

 maternal ovaries present, corpus luteum in each. The uterus 

 had been cut above the cervix and membranes injured; the fusion 

 of the two chorions was broad, and the cut ends of the arteries 

 connecting the two were readily discovered. 



