RECENT LITERATURE. 



Some Recent Zoological Text-books.— In the last few years 

 German zoologists have produced a considerable number of hand- 

 books, manuals and compendiums of zoology and its various sub- 

 divisions, the majority of which have been issued from a single 

 bouse, that of Fischer of Jena. The first requiring mention 

 is the zoology 1 by Boas of Copenhagen. This is in reality a second 

 edition of the Danish work of 1888, and the author acknowledges the 

 assistance received from Prof. Spengel in making the translation. It 

 differs from the original in many respects, the most noticeable being an 

 added section, entitled "Biologic" The work is divided into two 

 portions, general aud special, occupying respectively 90 and 475 pages. 

 In the first occur those general statements regarding cells, tissues aud 

 organs, the relation of animals to their environment, and the outlines 

 of the theory of evolution; which are deemed indispensable in the 

 ordinary text-book. In the special portion the various groups of the 

 animal kingdom are discussed. As must occur in a work by a single 

 author there is considerable inequality in the treatment, while a rather 

 reprehensible practice (not however confined to Dr. Boas) of treating 

 certain groups as appendages (Anhangen) of others result in some 

 rather queer associations. To show the scope and views of the author, 

 an outline of the classiBcation followed is here given. 1, Protozoa; 

 2, Coelenterates, with the sponges as an anhang ; 3, Echinodermata ; 4, 

 Plathelminthes (including Nemertines) with the Rotifers as an 

 anhang; 5, Nemathelminthes; 6, Annelida, with the Gephyrsea as an 

 anhang to the Chsetopods and separating them from the Hirudinei, 

 and with Polyzoa and Brachiopods as an anhang to the whole group ,* 

 7, Arthropoda divided into Crustacea, Myriapods, Insecta and 

 Arachnids; Limulus being inserted between Cladocera and Ostracoda, 

 the Stomatopoda following the Decapods; and Peripatus serving as 

 an anhang to the Myriapods; 8, Mollusca, arranged as follows: 

 Chitons, Gastropoda, Acephala, and Cephalopoda, the Pteropoda heing 

 closely associated with the OpUthobranchs ; 9, Vertebrata, divided 

 into Leptocardii, Pisces, Amphibia, Reptilia, Aves, and Mammals, 

 while the Tunicata occupy the last four pages of the volume of tbe 

 work, as an appendix to the Vertebrates. The work of Boas, as a 

 *Lehrbuch der Zoologie fur StuJirende und Lehrer, Dr. J. E. V. Boas, Jena, 1890, 

 pp. 578. 



