No. 389.] OVUM IN OVO. 4II 
example of the more common condition in which the included 
egg, an elongated ovoidal body, lay in the albumen. The yolk 
of the larger egg possessed a normal blastoderm. These writers 
gave a history of monstrosities of this class known up to that — 
time, from which the following abstracts are drawn. 
Davaine, in a work published in 1860, gave a résumé of cases 
of ovum in ovo then known. He found that the enclosing egg 
might be larger or smaller than normal, having shell, albumen, 
and yolk, the latter liable to deformity from disturbance of the 
foreign body. The included egg was very rarely of normal size ; 
usually it was small and devoid of yolk. Clayer, in 1682, 
described a case where the included egg was very small, but 
possessed a yolk. 
A similar example was also fe ici by Yung in1671. The 
yolk of the inside egg was very small, and possessed two 
chalaze. Rayer described, in 1849, a goose egg of colossal 
size, which contained an egg of normal dimensions, having 
yolk, albumen, and shell. The outer egg was also complete, 
although its yolk was flattened by pressure. A few years 
later three similar cases were reported by De Moroga, Aucapi- 
taine, and Alessandrini. The latter reported the case of an 
egg of normal size, which contained a small egg complete in 
all but the shell. 
In 1856 a case is cited, by Davaine, of three eggs enclosed 
by a common shell, and still later a precisely similar phenom- 
enon was described by Flourens. 
Panum,! who studied for several years the abnormalities of 
birds’ eggs and collected many examples, met with the ovum 
in ovo only once. This resembled Rayer’s goose egg, and 
came from the Indian jungle fowl. The inside body corre- 
sponded to the normal egg in size, while the surrounding egg 
was of relatively huge proportions. Panum adds that in 1858 
a remarkable egg of a Cochin China hen was described. It 
was very heavy and contained two yolks and one ordinary egg 
with solid shell. Still another egg, analogous to that of Rayer’s 
goose, was described by Bert in 1861. Patrona and Grassi 
1 Untersuchungen u. d. Entstehung d. Missbildungen. Berlin, 1860 (cited by 
Patrona and Grassi). 
