PEEFACE. 



This book has been written in the hope that it may meet the 

 wants of those who desire to obtain a practical acquaintance 

 with the elements of animal morphology, and who find the 

 existing manuals insufficient for their purpose. 



The animals selected for description are those which are 

 generally accepted as suitable types for a junior laboratory 

 course. They are of convenient size, and can all be obtained 

 readily and at small cost : they include characteristic repre- 

 sentatives of the more important of the great groups of 

 animals ; and they give opportunity for very varied methods 

 of examination. A student who works conscientiously 

 through the book will thus acquire a good insight into the 

 leading facts of animal structure, and a technical knowledge 

 of the principal methods of research. 



In the mode of treatment adopted the practical character 

 of the book has been made paramount. Directions for dis- 

 section have throughout been printed in italics, and a 

 system of indentation has been adopted to render the sub- 

 divisions more distinct. In almost all cases the descriptions 

 are so arranged that the whole dissection can be performed 

 on a single specimen : if more than one can be obtained, the 

 order in which the several sections are taken may be varied, 

 but in every case each of the main systems — vascular, nervous, 

 etc. — should be dissected in its entirety, for in this way alone 

 can a proper idea of its relations be obtained. 



