vi PKEFACE 



The illustrations are not meant to replace the drawings 

 which the student will be required to make as records of his 

 dissections and preparations. They are, on the whole, fresh 

 and original. I have to thank my colleagues of the Zoology 

 department of the University of Durham for help with some 

 of them : Mr. A. D. Peacock, M.Sc., for figures 10, 11, 12, and 

 the figures of the chapter on Insects ; Miss Olga M. Jorgensen, 

 M.Sc., for the illustrations to the chapter on Crustacea ; Mr. 

 F. W. Flattely, M.Sc., for figure 24 ; and Mr. B. Storrow, M.Sc., 

 for figures 43 and 44. I have further to thank Mr. Peacock 

 for help in reading the proofs. 



ALEXANDEK MEEK. 

 July 12th, 1922. 



