INTRODUCTION. XxXill 
certain fixed principles that the difficulties which present 
themselves on this point can be effectually overcome. 
If, in furtherance of this object, naturalists would only 
combine in adopting the excellent and very simple rules pro- 
posed by the eminent zoologists who were appointed a Com- 
mittee of the British Association for the express purpose of 
effecting a reform in zoological nomenclature, all confusion 
would speedily vanish, and science, instead of repelling the 
would-be student by its apparent complexity, would attract 
him by its real simplicity. 
For the present purpose it will not be necessary to mention 
more than three of the rules referred to; for, being the most 
im portant, they are those which have been more particularly 
ad hered to in the preparation of the present work. 
1. A species should be designated by the oldest name which 
has been published for it, to the exclusion of all subsequent 
synonyms. ‘This is termed “ the law of priority.” 
2. Linnzeus having originated the binomial system of no- 
menclature, and having published the last (12th) edition of 
his ‘Systema Nature’ in 1766 (which edition consequently 
may be taken to be as complete as he could make it), the 
“law of priority”? should not extend to any name bestowed 
upon a species prior to that date. 
3. The authority for a specific name, when not applying to 
the generic name also, should be placed in parentheses, other- 
wise not—e. g., Aquila chrysaétus (Linneus), Falco subbuteo, 
Linneus. 
Once admitting the propriety of such rules, the sooner they 
are carried into effect the better; for although it may be re- 
pugnant to the feelings of some to discard names with which 
they have become familiar, they should remember that these 
names may not be so familiar to others, and the only names 
which should really be so to all are those only which can be 
