X PREFACE. 



tion of the objects under investigation without a direct ac- 

 quaintance with them. Tt is indeed desirable that the author 

 of a work of this kind should have examined all the species, 

 and in various distant localities, that he may justly charac- 

 terize them, and estimate the extent of their variations ; nor 

 was the circumstance of the comparative unmovableness to 

 which a medical practitioner is doomed unconsidered as a bar 

 to my own competency, but the love of the subject prevailed, 

 especially when friends were readily found to contribute to 

 the removal of the difficulty. To them I have in this place 

 to render my grateful acknowledgments. To Mr. Bean of 

 Scarborough, Dr. Coldstream of Leith, J. V. Thompson, Esq., 

 Inspector of Hospitals, for some time resident in Cork, and 

 the Eev. David Landsborough of Stevenston in Ayrshire, I 

 stand indebted for numerous specimens ; and similar commu- 

 nications of less extent have been sent me in a friendly 

 manner by John Edward Gray, Esq., of the British Museum ; 

 Mr. Robert Embleton, surgeon in Embleton ; Messrs. Alder 

 and Bowman of Newcastle ; Mr. Teale of Leeds ; J. Hogg, 

 Esq., of Norton ; and Messrs. Macgillivray and P. W. Mac- 

 lagan of Edinburgh. One other name must not be forgotten, 

 for, besides a friendly interest in the book, and his revision of 

 it during its progress through the press, I have had the kind 

 assistance of the Eev. Thomas Riddell, of Trinity College, 

 Cambridge, whenever the assistance of a classical scholar was 

 required. 



I am not certain that any apology will be deemed necessary 

 for the notes and quotations which have been introduced with 

 considerable liberality, for the tastes of the naturalist have 

 ever seemed to me akin to those of the antiquary ; and this 

 has always been a favourite mode of illustration with the 

 latter. It is one that chimes in with my own humour, and 

 the indulgence of it seemed at least harmless on the present 

 occasion. Many of these notes are devoted to notices of 



