PREFACE 



Rats can usually be obtained in large quantities in any 

 community if proper trapping methods are used; conse- 

 quently the rat provides an excellent subject for dissection 

 at colleges in communities where cats or dogs are difficult 

 to obtain. This manual was written to supply laboratory 

 guidance in the study of the rat because it is an inexpensive 

 mammal which is easy to obtain. 



The literature on the gross anatomy of this rodent is not 

 extensive. Much of the material in the manual is therefore 

 the result of the w^riter's own investigations, which were 

 carried on at intervals at the University of Mississippi 

 since the summer of 1920. No attempt has been made in 

 the text to indicate those sections which are wholly the 

 result of the author's work or those for which informa- 

 tion was obtained from other sources. 



Instructors can use the manual for elementary classes by 

 omitting those sections which they deem of lesser im- 

 portance, or it can be used in its entirety for classes in 

 advanced vertebrate anatomy. Illustrations have been pur- 

 posely omitted, because it is better for the student to get 

 his visual impressions from the animal itself. Either the 

 wild Norway rat or its albino variety may be used. 



Acknowledgment for limited assistance is due to Martin 

 and Moale's ''Handbook of Vertebrate Dissection," Part 

 III (1884). The writer extends special credit and thanks to 

 Mrs. Eunice Chace Greene, formerly of the zoological teach- 

 ing staff of Smith College, who has very generously read 



