ingdoms and classes, and by
treating each class under both points of view; and finally, by fascinating
experiments to bring before us in detail the hypothetical pedigrees of all
classes of organisms from the protista kingdom up to man.

We will try to reproduce briefly the pedigree which is of most
interest--the hypothetical _pedigree of man_. Haeckel divides it into
twenty-two stages, eight of them belonging to the series of the
invertebrates, and fourteen to that of the vertebrates. On this ladder of
{47} twenty-two rounds, he leads us from the lowest form of the living
being, in slight and mostly plausible transitions, continually higher and
higher, up to man; and makes our steps easy by mentioning at each stage, on
the one hand the corresponding state in the embryonic development, on the
other the still living creature through which, in his opinion, the former
organisms of the corresponding round of the ladder are still represented,
and which accordingly has been a creature that remained on its round, while
other members of its family have been developed up to man and to many other
genera and species.

He begins with the monera, the organisms of the lowest form, discovered by
himself, which have not so much as the organic rank of a cell, but are only
corpuscules of mucus, without kernel or external covering, called by him
cytod, and arising from an organic carbon formation. The lowest and most
formless moneron is the bathybius, discovered by Thomas Huxley, a network
of recticular mucus, which in the greatest depths of the sea, as far down
as 7,000 metres, covers stone fragments and other objects, but are also
found in less depths, in the Mediterranean Sea, for instance. From the
moneron he proceeds to the amoeba--a simple cell, with a kernel, which
still corresponds to the egg of man in its first state. The third stage is
formed by the communities of amoebae (synamoebae), corresponding to the
mulberry-yolk in the first development of the fecundated egg, and to some
still living heaps of amoebae. To the fourth stage he assigns the planaea,
corresponding to the embryonic development of an albumen and the planula or
ciliated {48} larva. When these ciliated larvae are developed, they contract
themselves so as to form a cavity; and this fifth stage--especially
important for his theory--he calls gastraea. In this form, he says, the
progaster is already developed, and its wall is differentiated for the
first time into an a