ACTION OF SEX HORMONES IN FOETAL LIFE 411 



Figure 22. Case 4. Bovine twins cf' and ^. Collected 

 January 30, 1915. Male 24 cm., female 22.5 cm. Single chorion, 

 constricted between the two foetuses. No other records. 



Figure 23. Case 38. Bovine twins d" and?". Collected 

 January 26, 1916. Male 23.5 cm., female 22.5 cm. Both ma- 

 ternal ovaries present, corpus luteum in each. The uterus was 

 received cut off above the cervix severing the connecting part 

 of the chorion. The large vessels run to cut ends; extensive 

 vascular anastomosis between the two foetuses involved. 



Figure 24. Case 22. Bovine tmns d" and ^. Collected 

 October 26, 1915. Male 24.5 cm., female not measured. Both 

 maternal ovaries present, corpus luteum in each. Uterus cut 

 into destroying connection of the two halves of the chorion; the 

 chorion was single and the maternal cotyledons occurred through- 

 out the corpus uteri. Vascular conditions of chorion not 

 observed. 



Figure 25, A and B. Case 21. Bovine twins d and ^ . Col- 

 lected October 20, 1915. Male 27.5 cm., female 26.5 cm. Ma- 

 ternal ovaries absent. The two halves of the chorion were 

 broadly connected, and cotyledons and blood vessels cross over 

 from side to side. 



Figure 26. Case 14. Bovine twins cT and ^. Collected 

 July 15, 1915. Male 27 cm. long; female 27 cm. long (meas- 

 urements by assistant) . Maternal ovaries absent ; the two halves 

 of the chorion were broadly connected with cotyledons and 

 arteries crossing over. 



Figure 27. Case 12. Bo\nne twins cf and ^. Collected 

 October 2, 1915. Male 30 cm., female 28 cm. long. Maternal 

 ovaries absent. The chorion was single, not much constricted 

 between foetuses. Cotyledons form continuous series from side 

 to side. No observations on vascular conditions of chorion. 



The gross anatomy after birth 



The anatomy of the reproductive organs of a seven weeks old 

 free-martin (case 44) born on my farm is shown in figure 28. 

 Incidentally it may be noted that the twins were pure bred 

 Holsteins, and that while the male was mostly black, the female 



