PREFACE 



THE object of this volume is to provide a text-book for the zoological 

 portion of the syllabus in Biology for the First Examination for 

 Medical Degrees of the University of London, and the First Examina- 

 tion for the Conjoint Examining Board in England of the Royal 

 College of Physicians of London and the Royal College of Surgeons 

 of England. Some years' experience in preparing fairly large classes 

 of students for the above examinations made quite clear the need 

 for such a text in spite of the text-books of Zoology available. It 

 is based on the lectures then given, and its method of treatment is 

 that found to suit the needs of the students. It is hoped that it will 

 also prove useful to students preparing for similar examinations of 

 other British Universities, and for those who are taking classes, 

 like the premedical courses in American Universities, requiring a 

 knowledge more particularly of Vertebrate Zoology. 



The above requirements have naturally determined in the main 

 the types studied, but the syllabus has not been slavishly followed 

 in places where it was considered the student would benefit by 

 considering examples outside it. Types like the Crayfish, Astacus, 

 the Fresh-water mussel, Anodon, and the Cockroach, Periplaneta, 

 often included in elementary books, have been omitted. This was 

 done because it was felt that the knowledge of such specialised types, 

 while essential to a student proceeding with the more advanced 

 study of Zoology, involve a great deal of detail unnecessary from the 

 point of view of students proceeding with medical studies, and, 

 moreover, they do not illustrate any fundamental principles that 

 cannot also be dealt with in connection with the types chosen. The 

 space so gained has been utilised to describe fairly fully the structure 

 of a mammalian skull, that of the dog, of a mammalian heart, that 

 of the pig or sheep, and of a mammalian brain, that of the sheep. 

 While the detail in these cases is perhaps rather more than required 

 for examination purposes, it is hoped that their study will be of 

 value in the subsequent work in Anatomy. Then, too, Cytology, 

 Histology, and Embryology have received fuller treatment than is 

 usually the case, since they are subjects of importance in future 



V 



513264 



