258 Sir Everard Home on the passage of the ovum 
In proof of menstruation not being necessary for impreg- 
nation, I shall mention the following case. A young woman 
was married before she was seventeen, and, although she 
had never menstruated, became pregnant ; four months after 
her delivery she became pregnant a second time, and four 
months after the second delivery she was a third time preg- 
nant, but miscarried ; after this she menstruated for the first 
time, and continued to do so for several periods, and again 
became pregnant. 
I have given Mr. Bauer’s account of the ovum, and the 
drawings he has made of it, in his own words, than which 
none can be more clear or satisfactory. 
“ On closely examining the subject under the microscope, I 
found it consisted of membrane, which, considering the ex- 
treme minuteness of the subject, is of considerable thickness 
and consistence, very little transparent, quite smooth, and 
milk white, forming a kind of bag or pouch of an irregular 
oval shape, not quite parts of an inch in length, and in its 
middle about parts of an inch broad ; on one side it has an 
elevated ridge or large fold along the whole length, and on 
the opposite side it is open nearly the whole length, but has 
no appearance of being torn, the edges of the membrane 
being smoothly rolled inwards, which gives it much the 
shape of a little shell of the genus Voluta. 
44 When laid on glass, the membrane admitted easily to be 
laid open on both sides, with the point of a fine camel hair 
pencil. When thus opened, I found it contained another 
smaller bag somewhat less than parts of an inch long, 
and not quite parts of an inch broad, ending at the upper 
extremity nearly in a point, but the under extremity was 
very obtuse or truncate, and in the middle it was slightly 
