dissimilar to that of a dog as the bud-like limbs are unlike his legs.

The remains of the yelk, which have not yet been applied to the
nutrition and growth of the young animal, are contained in a sac
attached to the rudimentary intestine, and termed the yelk sac, or
'umbilical vesicle.' Two membranous bags, intended to subserve
respectively the protection and nutrition of the young creature, have
been developed from the skin and from the under and hinder surface of
the body; the former, the so-called 'amnion,' is a sac filled with
fluid, which invests the whole body of the embryo, and plays the part of
a sort of water-bed for it; the other, termed the 'allantois,' grows
out, loaded with blood-vessels, from the ventral region, and eventually
applying itself to the walls of the cavity, in which the developing
organism is contained, enables these vessels to become the channel by
which the stream of nutriment, required to supply the wants of the
offspring, is furnished to it by the parent.

The structure which is developed by the interlacement of the vessels of
the offspring with those of the parent, and by means of which the
former is enabled to receive nourishment and to get rid of effete
matters, is termed the 'Placenta.'

It would be tedious, and it is unnecessary for my present purpose, to
trace the process of development further; suffice it to say, that, by a
long and gradual series of changes, the rudiment here depicted and
described becomes a puppy, is born, and then, by still slower and less
perceptible steps, passes into the adult Dog.

There is not much apparent resemblance between a barndoor Fowl and the
Dog who protects the farm-yard. Nevertheless the student of