THE COAL TITMOUSE. 107 



britannicus ; but, having carefully read their descrip- 

 tion and examined the specimens on which their 

 remarks were founded, we are compelled to say 

 that we regard the differences indicated by them as 

 too slight to warrant a specific separation. In our 

 humble opinion it amounts to nothing more than an 

 individual variation. And here \ve may be per- 

 mitted to express our regret at the growing practice 

 which (unfortunately, we think, for science) is 

 sanctioned by many leading ornithologists of seiz- 

 ing upon minute and unimportant variations of 

 colour upon which to found and name new species. 

 In such forms as Parus britannicus, Parus persicus, 

 Acredula irbii, Gecinus sharpii, Erythacus hyrcanus, 

 and a host of others, we fail to see anything more 



I than a slight variation of colour, which may be well 

 m 

 accounted for by the differences of soil, food, and 



climate, to which these various forms are naturally 

 subjected. We must not, however, be understood 

 to imply that these slight variations of colour should 

 be disregarded or ignored ; on the contrary, their 

 detection is rather to be commended, inasmuch as 

 they may help, when made known, to fix approxi- 

 mately the origin, or country, of any particular 



