Vi PREFACE TO THE FOURTH EDITION 



drawn from photographs taken from actual dissections by 

 the writer. One specimen had a persistent jugular lymph sac 

 and this has been added to the figure to show its position and 

 venous tap. Certain other variations are shown also. The 

 writer will be glad to receive communications regarding varia- 

 tions in any of the systems as well as criticisms and suggestions. 

 The aim has been to make the text as concise as possible and 

 to keep to the present convenient size of the book as nearly 

 as possible. The index has been very much enlarged to make 

 it more useful. 



Frank A. Stromsten. 



