INTRODUCTION. 11 



of the Invertebrates' 3 (Appleton). Of these Lang's work 

 is the most detailed; Huxley's is rather old; Shipley's is 

 the simplest. The structure of the vertebrates will be 

 found in Wiedersheim's "Comparative Anatomy of the 

 Vertebrates" (Macmiilan), Huxley's "Anatomy of the 

 Vertebrates" (Appleton), and Kingsley's "Vertebrate 

 Zoology" (Holt). 



The development of animals is discussed in the following 

 works: Balfour's "Treatise on Comparative Embryology' 

 (Macmillan), Korschelt and Heider's "Text-book of Em- 

 bryology' (Macmillan), Hertwig's "Text-book of Em- 

 bryology "(Macmillan), and Minot's "Human Embryology' 

 (Wm. Wood & Co.). Balfour's treatise is a standard, but 

 is rather old. Korschelt and Heider deal only with in- 

 vertebrates; Hertwig and Minot only with vertebrates. 

 McMurrich's "Development of the Human Body' (Blak- 

 iston) is a smaller work treating almost entirely of the 

 development of mammals. 



Within a few years several good general zoologies have 

 been published. Under this head are included works 

 which treat of the structure, development, classification, 

 etc., of animals. Prominent among these are the "Text- 

 book of Zoology' by Parker and Haswell (Macmillan) 

 and Kingsley's translation of Hertwig's "Zoology" (Holt). 

 Larger works are the "Cambridge Natural History' and 

 a "Treatise on Zoology' (Macmillan), now in course of 

 publication. The "Riverside Natural History' (Hough- 

 ton, Mifflin & Co.) and the "Royal Natural History" are 

 more popular in character. Among the more elementary 

 works may be mentioned the zoologies of Jordan and 

 Kellogg, Colton, Weysse, and Davenport. 



The broader and more general biological principles, 

 without reference to classification and description of forms, 



