xviii. Introduction 



surely this is a case where it should do so. The very terra subspecies 

 implies the recognition of the species as a higher grade, and this can 

 only be carried out by retaining the original binomial name of that 

 species in its pristine integrity. 



With regard to subspecies or local forms, I may observe that I am 

 distinctly in favour of recognising such forms, provided they are 

 constant in their variation, within their range or sphere of habitat. 

 It would, indeed, be contrary to the advancement of science not to do 

 so, and no true lover of Nature would wilfully close his eyes to their 

 recognition. It is, moreover, a highly interesting and instructive 

 study to follow the working of Nature in this respect, and one, which 

 if patiently and perseveringly carried out, cannot fail to teach us much 

 in connection with the mutability of species and the formation of new 

 species. 



On the other hand, though strongly in favour of recognising sub- 

 species or local forms, I need hardly observe that I am entirely 

 opposed to doing so on insufficient grounds. Unfortunately there has 

 recently been, I fear, far too much " splitting," based often on most 

 slender grounds, at times on mere individual variation, and this, in 

 some cases, even on the part of good and conscientious ornithologists, 

 who, in their zeal and ardour, have been too prone to grasp at what 

 may at first sight have appeared plausible and sound argument for 

 their conclusions. I trust I may not be accused of having myself 

 erred in this respect, but should I unwittingly have done so, I shall 

 1)0 quite ready to admit my fault and cry "peccavi." 



Most of the descriptions of birds given in my work are of examples 

 in my own collection, and when it has been possible, particularly as 

 regards the measurements and soft parts, they have been taken from 

 freshly-killed specimens. 



The few plates in the work are of some of the more interesting 

 species which occur in Tunisia, and testify to the artistic ability of 

 their author, Mr. H. Gronvold, to whom I am much indebted for the 

 care and attention devoted to their execution. 



Messrs. Mintern Brothers have carried out the lithograph printing 

 in their customary excellent style. 



The colouring of some of the illustrations has been undertaken by 

 Miss Dora Bowdler Sbarpe, and bear testimony to that lady's fine 

 touch ; the remainder and greater part have been carefully coloured by 

 Mr. G. Edwards. 



The printing of the text throughout, together with the Photo- 



