Under Darwin's hand! for I shall have nothing to do
except just to place the building stones in the position which his
theory indicates for them. "When kings build, the carters have to work."
CHAPTER 7. DEVELOPMENTAL HISTORY OF PODOPHTHALMA.
Let us first glance over the extant facts.
Among the Stalk-eyed Crustacea (Podophthalma) we know only a very few
species which quit the egg in the form of their parents, with the full
number of well-jointed appendages to the body. This is the case
according to Rathke* in the European fresh-water Crayfish, and according
to Westwood in a West Indian Land Crab (Gecarcinus). (* Authorities are
cited only for facts which I have had no opportunity of confirming.)
Both exceptions therefore belong to the small number of Stalk-eyed
Crustacea which live in fresh water or on the land, as indeed in many
other cases fresh-water and terrestrial animals undergo no
transformations, whilst their allies in the sea have a metamorphosis to
undergo. I may refer to the Earthworms and Leeches among the Annelida,
which chiefly belong to the land and to fresh water,--to the Planariae
of the fresh waters and the Tetrastemma of the sparingly saline Baltic
among the Turbellaria,--to the Pulmonate Gasteropoda, and to the
Branchiferous Gasteropoda of the fresh waters, the young of which
(according to Troschel's 'Handb.
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