762 REVIEWS AND BOOK NOTICES. 
book knowledge could write like this. We would inquire whether 
what we know of the embryology of the Comatula from the re- 
searches of Wyville Thompson does not point to the evolution of | 
the Crinoids from the lower Radiates, the Acalephs, and further 
on from the Hydra? From the researches of Miiller, Professor 
Agassiz and Mr. A. Agassiz, the embryos of the three classes 
seem readily homologized, and the forms of the embryo of the 
starfish which so strikingly resembles some worms, such as Sipun- 
culus, Balanoglossus and Nemertes for example, are perhaps the 
result of similar modes of life, and not of genetic significance ; 
farther than that they possibly indicate a protozoan origin. Again, 
the inadequacy of the author’s knowledge of the invertebrates is 
conspicuous in the statement on page 44 that the “centipedes, 
` insects and spiders are joined in one division, Tracheata,” when 
any text book would have told him that the spiders do not have - 
trachee. While, as he says, the Myriopods are composed of 
numerous segments, “in the insect we can distinguish only three 
segments known as head, thorax and abdomen.” ... - i 
‘the Arachnida we find only two segments [!!].” A moment's 
glance at a specimen would have saved such a sad blunder. The 
matter is scarcely mended by the statement on the next page that 
“the numerous segments of which the immature insect and spider 
are composed gradually coalesce, until finally the perfect insect 
exhibits only three pieces, the spider two.” 
Though the portion on the invertebrates is often weak and 
faulty, the remaining chapters seem to be more carefully prepared, 
though the tone of the book, like Hackel’s, is that of an advocate, - 
the adverse facts being kept in the background. Read with due 
caution, the book is a fair résumé of the opinions of many able 
naturalists as to the probable mode of development of man and 
_ the lower.organisms. 
ILLUSTRATIONS or Norta Americas Morns.*—This is a valu- 
able work and worthy of all encouragement, as it gives systematic 
descriptions (compiled when the author has not had specimens) of 
the North American (north of the Mexican boundary) species of two 
extensive and most interesting groups of moths. It offers good 
* Illustrations of the Zygænidæ and Bombycidæ of North America. By R. H. eee i 
í Vol. 1, parts 1-5. San Francisco, 1872. 8vo. E p es. Price, uncol abet 
T5 cents a number; colored, $1.00. Send subscriptions to author, or the Naturalist’ : 
Agency. 
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