PREFACE I 



the work here outlined for the dissection of the dogfish head 

 and sheep and human brains and for the study of the micro- 

 scopic sections as directed, the sections being supplied from the 

 departmental loan collection. The "optional dissections" of 

 the human brain (sections 102 to 111, 141 to 152) are omitted, 

 or are done by some students in extra time or in a more ad- 

 vanced course. 



The Authors. 

 Chicago, III., 

 January, 1918. 



