that after the act of insemination, sperm was
carried to each ovary; that one had matured a germ ready for
fecundation, then impregnation and conception immediately followed, and
the decidua of the uterus hermetically sealed both Fallopian tubes, and
thus securely retained the sperm within the other Fallopian canal. The
stimulus of the sperm so pent up causes that ovary to mature a germ,
although it may do so slowly, and after two or three months it is
perfected, fertilized, and a second conception occurs within the uterus.
If each embryo observe a regular period of growth and each be born at
maturity, there must be an interval of two or three months between their
births. But it is far more common for the parturition of the first,
displaying signs of full maturity, to coincide with the birth of a
second which is immature and which cannot sustain respiratory life. The
birth of the latter is brought about prematurely, by the action of the
uterus in expelling the matured child.

UTERINE PREGNANCY.

There are many who manifest a laudable desire to understand the
physiology of conception, the changes which take place, and the order of
their natural occurrence. When impregnation takes place at the ovaries
or within the Fallopian tubes, there is exuded upon the inner surface of
the womb a peculiar nutritious substance. It flows out of the minute
porous openings surrounding the termination of the Fallopian tube within
the uterine cavity, and, thus, is in readiness to receive the germ, and
retain it there until it becomes attached. Undoubtedly, the germ imbibes
materials from this matter for its nurture and growth. This membranous
substance is termed the _decidua_, and disappears after conception is
insured. Two membranes form around the embryo; the inner one is called
the _amnion_, the outer one the _chorion_. Both serve for the protection
of the embryo, and the inner one contains the _liquor amnii,_ in which
it floats during intra-uterine life. Immediately after conception, the
small glands in the neck of the uterus usually throw out a sticky
secretion, filling the canal, or uniting its sides, so that nothing can
enter or leave the uterine cavity.

The fertilized ovum rapidly develops. After its conception it imbibes
nourishment, and there is a disposition in fluids to pass into it,
through its delicately-organized membranes. If this process is not
involuntary, it is, at all events, at the convenience and use of the
dev