uterus is furnished with cornua, or is partially divided into two organs;
and such cases, according to Owen, repeat "the grade of concentrative
development," attained by certain rodents. Here perhaps we have an
instance of a simple arrest of embryonic development, with subsequent
growth and perfect functional development; for either side of the partially
double uterus is capable of performing the proper office of gestation. In
other and rarer cases, two distinct uterine cavities are formed, each
having its proper orifice and passage. (39. See Dr. A. Farre's well-known
article in the 'Cyclopaedia of Anatomy and Physiology,' vol. v. 1859, p.
642. Owen, 'Anatomy of Vertebrates,' vol. iii. 1868, p. 687. Professor
Turner, in 'Edinburgh Medical Journal,' February, 1865.) No such stage is
passed through during the ordinary development of the embryo; and it is
difficult to believe, though perhaps not impossible, that the two simple,
minute, primitive tubes should know how (if such an expression may be used)
to grow into two distinct uteri, each with a well-constructed orifice and
passage, and each furnished with numerous muscles, nerves, glands and
vessels, if they had not formerly passed through a similar course of
development, as in the case of existing marsupials. No one will pretend
that so perfect a structure as the abnormal double uterus in woman could be
the result of mere chance. But the principle of reversion, by which a
long-lost structure is called back into existence, might serve as the guide
for its full development, even after the lapse of an enormous interval of
time.

Professor Canestrini, after discussing the foregoing and various analogous
cases, arrives at the same conclusion as that just given. He adduces
another instance, in the case of the malar bone (40. 'Annuario della Soc.
dei Naturalisti,' Modena, 1867, p. 83. Prof. Canestrini gives extracts on
this subject from various authorities. Laurillard remarks, that as he has
found a complete similarity in the form, proportions, and connection of the