It possesses a value quite independent of its reference to Darwinism,
due to the number of highly interesting and important facts in the
natural history and particularly the developmental history of the
Crustacea, which its distinguished author, himself an unwearied and
original investigator of these matters, has brought together in it. To a
considerable section of English naturalists the tone adopted by the
author in speaking of one of the greatest of their number will be a
source of much gratification.

In granting his permission for the translation of his little book, Dr.
Fritz Muller kindly offered to send some emendations and additions to
certain parts of it. His notes included many corrections of printers'
errors, some of which would have proved unintelligible without his aid,
some small additions and notes which have been inserted in their proper
places, and two longer pieces, one forming a footnote near the close of
Chapter 11, the other at the end of Chapter 12, describing the probable
mode of evolution of the Rhizocephala from the Cirripedia.

Of the execution of the translation I will say but little. My chief
object in this, as in other cases, has been to furnish, as nearly as
possible, a literal version of the original, regarding mere elegance of
expression as of secondary importance in a scientific work. As much of
Dr. Muller's German does not submit itself to such treatment very
readily, I must beg his and the reader's indulgence for any
imperfections arising from this cause.

W.S.D.

LONDON, 15TH FEBRUARY, 1869.