148 MALL. [VoL. XIX. 
Since the first publication of this specimen, embryos both 
normal and pathological have been studied, all of which indi- 
cate more and more that this specimen must belong to the 
pathological class. The other pathological specimens in my 
collection as well as the perfect normal specimen described 
recently by Peters all speak for this conclusion. Yet the 
presence of all three blastodermic membranes in it, with blood 
islands in the mesoderm, and an allantois in the embryonic 
stem, indicate that this specimen cannot be far from the 
normal, but represents the earliest changes in the blastodermic 
membranes in a specimen of the Peters’ stage under path- 
ological conditions. 
Fic. 12a—Photograph of the entire ovum. Natural size. 
No. 12. 
Ovum, 20 20.10m. embryo.cC oho 2s neni. 
From Dr. Ellis, Elkton, Md. 
“The patient from whom the ovum was obtained is twenty- 
three years old, menstruated first in her fourteenth and mar- 
ried in her twentieth year. Some time after her marriage 
she became pregnant and aborted July 6, 1893, having passed 
two periods at that time. The next time she became preg- 
nant she aborted this specimen. She was last unwell Novem- 
ber 7, the flow lasting five days, and she aborted on the 18th 
of December, that is, I found the ovum in the discharges of 
that day, although the waiting began the day before. The 
patient says it has always been her habit to go more than 
twenty-eight days, her periods recurring on the thirtieth day 
usually, but frequently the intervals are longer, thus: She 
was unwell on October 5 and on November 7 and in Sep- 
