viii PEEFAtJE 



No attempt has been made to write exhaustive descrip- 

 tions of the several animals ; neither has strict uniformity of 

 treatment been specially aimed at. Portions of the subject 

 which experience has shown to present special difficulties 

 are treated at what may appear undue length ; while, on 

 the other hand, the limits of time ordinarily available for 

 laboratory work have led to the almost entire omission of 

 systems, such as the muscular, which are of subordinate 

 educational value. 



Although this is essentially and professedly a laboratory 

 text-book, yet morphological explanations have been freely 

 introduced; and this from a conviction that a student best 

 grasps the meaning of anatomical facts if the explanation 

 is given him while the facts are actually before his eyes. 



Illustrations have been introduced somewhat sparingly, 

 for it is of the utmost importance that they should not be 

 allowed to replace the drawings which a student must make 

 from his own dissections. The majority of the figures here given 

 are new, and have been drawn expressly for the book by Mr. 

 Hurst or myself. The drawings on the wood were made by 

 Mr. P. Hundley, and the blocks engraved by Mr. G. Pearson : 

 both these gentlemen have taken great pains to render the 

 figures at once faithful and artistic. 



Throughout the whole time of preparation of this volume 

 I have had the constant co-operation and assistance of my 

 friend Mr. C. H. Hurst. S.everal of the chapters were 

 originally drawn up by him, and in all I have had the ad- 

 vantage of his aid, but for which the publication of the book 

 might have been greatly delayed. Considerable pains have 

 been taken to avoid mistakes, but it is curiously difficult to 

 succeed in this, and corrections or suggestions from those who 

 use the book will be very gratefully received. 



A. M. M. 

 Owens College : December 1886. 



