14 THE NATUKAL HISTOEY OF THE COMMON CRAYFISH. 



denote that which the Greeks, ancient and modern, 

 signify, by its original, astaJws ; and does signify 

 something quite different. 



Finally, as to why it is needful to have two names 

 for the same thing, one vernacular, and one technical. 

 Many people imagine that scientific terminology is a 

 needless burden imposed upon the novice, and ask us 

 why we cannot be content with plain English. In reply, 

 I V70uld suggest to such an objector to open a conversation 

 about his own business with a carpenter, or an engineer, 

 or, still better, with a sailor, and try how far plain 

 English will go. The interview will not have lasted long 

 before he will find himself lost in a maze of unintelligible 

 technicalities. Every calling has its technical termin- 

 ology ; and every artisan uses terms of art, which sound 

 like gibberish to those who know nothing of the art, but 

 are exceedingly convenient to those who practise it. 



In fact, every art is full of conceptions which are 

 special to itself ; and, as the use of language is to convey 

 our conceptions to one another, language must supply 

 signs for those conceptions. There are two ways of 

 doing this : either existing signs may be combined in 

 loose and cumbrous periphrases ; or new signs, having 

 a well-understood and definite signification, may be in- 

 vented. The practice of sensible people shows the 

 advantage of the latter course ; and here, as elsewhere, 

 science has simply followed and improved upon common 

 sense. 



