134 SPRINGTIME SURGERY 



exceedingly rare; far rarer than cases where 

 double conception has resulted from connection 

 with two different males at intervals separated 

 only by a few hours. Fleming records cases 

 where women have borne twins, one white and 

 one mulatto, from copulation with a white man 

 following that with a negro or vice versa, and 

 similar cases where a horse and a mule colt were 

 delivered at one birth when service with a horse 

 and a jack was had on the same day. These are 

 cases of superfecundation. 



The more remarkable instances are those in 

 which conception has occurred from two copula- 

 tive acts, weeks or months apart (superfetation), 

 and where each fetus is carried for the full period 

 of gestation. One of these cases occurred in New 

 York in 1876. A five-year-old mare bore a fully- 

 developed, well-formed dead colt on February 

 twenty and on the second of April another sound, 

 healthy fully-developed live colt. Other cases in 

 which two fetuses in different stages of develop- 

 ment have been delivered at one birth are more 

 frequent. The following case of this kind re- 

 cently came under my observation. 



