REVIEWS. 555 
a This treats of general principles, and is to be understood as being in- 
troductory, while the remaining parts will be devoted to the structure 
phical gaea to which is to be added ‘a briefly descrip- 
tive catalogue of the birds of the Middle "o r «of many of the 











practical value to scie 
In this first part ae writer very appropriately devotes several pages to 
an account of the structure of the egg, and the mode of dev elopment of 
ations in the color and texture of the shell. The greater part, however, 
i is devoted to a discussion of the classification of birds; a new or consid- 
erably modified system of which is proposed. It shows that the writer 
has given the subject piled emis thought, and is in many points highly 
emendable, in fact approaching in general more nearly to the natural 
puted) highest authorities. We scarcely see the propriety, however, of 
making a third sub-class of the S and the Dodo, and their respective 
allies, nor of dispers ing the Proecoces so widely among the Altrices, as is 
done, not only in the present case but generally. The subdivision, by Oken 
(according to Agassiz, by Bonaparte as generally received), of birds into 
o grand divisions, be they sub-classes or orders, seems to have been & 
the occurrence of representative groups in each, seems eee ee, 
rate their naturalness. 
Bs te wis’s modes tly written book, however, seems likely to supply & 
gap in our ornithological literature, and as it ee os 
_ Of originality, and promises a clearly expressed aona CEE 
State of the science, we heartily comme end it as a work fully entitled to 
aneron aay ae «Ake 
ee THE Sc N PUBLICATIONS IN NATURAL HISTORY 
punso ir. AND PART OF 1868.t (In a letter from Dr. Lütken of Copen- 
| ta le ee 

“he Naturalist’ 
s Book Agency will supply this work at 35 cents a part. 
posta a A in the pene Zoological Mu- 
}Dr. C, F, Liitken, an accomplished naturalist ahd assistant 
eae at Copenhagen, has kindly IE to prep or A , a yearly review 
h to va o; atural History in ndinavia, of whieh the aches pi pies end pote 
Conch concluded in the next number, relates to the literature of De mark and Norway. Ci 
tuston, embra a and Piniand, will Siow soon. AA ihom Nore am e 
yr essible, containing papers by the most thorough and reliable observers 
inacces 
Northern 
eee ee we think the readers of the NATURALIST are especially "o Sien yig sen 

