AND PREGNANCY. 371 



virgin is sufficient frequently to effect the discharge of ova. It 

 is perhaps impossible otherwise to explain the fact that ova are 

 so commonly expelled from the ovaria and impregnated when- 

 ever a connection is arbitrarily or casually brought about. Hen 

 pigeons, if kept with males, lay not only at an earlier age, but 

 all the year round, instead of merely in the spring. 



How the semen operates upon the ovarian secretion in fecun- 

 dating and transmitting the paternal peculiarities, is a mystery 

 impenetrably concealed from human curiosity. 



4. The rupture of the ovarium has been said not to occur till 

 some time subsequent to coition. Mr. Cruikshank did not see 

 ova in the Fallopian tubes of rabbits, nor orifices in the corpora 

 lutea, till the third day from copulation,* nor ova in the uterus 

 till the fourth. Dr. Haighton never found any thing of a regular 

 form in the uterus before the sixth day. 



(B) An instance of superfoetation of the description granted 

 by Blumenbach occurred to Mr. Blackaller of Weybridge. A 

 white woman of very loose character left her husband, and some 

 time afterwards returned pregnant to her parish and was delivered 

 in the workhouse of twins, " one of which," says Mr. Blackaller 

 in an account which he very handsomely sent me, % was born 

 of a darker colour than I have usually observed the infants of 

 negroes in the West Indies ; the hair quite black with the 

 woolly appearance usual to them, with nose flat and lips thick :" 

 the second child had all the common appearances of white 

 children. 



The uterus has been sometimes wanting, f sometimes desti- 

 ute of anterior opening, % an d sometimes double, § in which 

 ast case we may imagine superfetation possible at any period 

 ifter the first conception, provided each uterus have a distinct 



* De Graaf and Valisneri met with the same results, 

 f Lieutaud, Sandifort, Morgagni, Stein, Theden, Schmucker, Engel. 

 X Louis. 



§ Ephemerid. Natur. Curios. Dec. 3. Ann. 7 and 8. Obs. 35. Cent. 9. Obs. 75, 

 j hilos. Trans, vol. 4. 1699. . 



2b2 



