( xlix ) 



we know that bad money often gets into circulation, but when 

 detected is forthwith destroyed, or at least withdrawn from 

 currency, and is never allowed to be again used, so the bad 

 descriptions which are the bad coins of the Scientific World 

 should in a similar way be destroyed or withdrawn for ever 

 from circulation as soon as they are detected. I hold that the 

 good currency of the civilised Scientific World is based on the 

 genuine coin of good description, and not on the barter of 

 interchange, and farther that this good coin of " good descrip- 

 tion " must be uttered from some recognised aud accepted 

 " Mint," and not be put forth from some unrecognisable Hun- 

 garian, Russian, or Japanese circulations which could oidy be 

 accepted in their own limited area. One point further still : 

 we know that when coinage was not carried out so caref idly 

 as it is at present that local towns and even local tradesmen 

 issued " tokens " which were exchangeable in those towns or 

 with those ti-adesmen for goods of the value of some mintage 

 coin, but that those tokens possessed no i-ecognised value out- 

 side of the district in which they circulated. I consider, by 

 the same reasoning, that the publications of new species or 

 even varieties in the papers issued by local Societies only 

 represent "tokens" whicli, although ihey may be of the 

 same value as the corresponding mintage coin in their own 

 area, yet are not legal tender outside a limited district, and 

 consequently should not be accepted as a cii-culating medium. 

 It is of course possible that occasionally a good coin may be 

 mistakeia for a bad one, and in all such cases, of which I 

 could give many, the coin (or description) must be reinstated 

 to its original value. 



One other point on types. It is very frequently the case that 

 in old collections only one or two specimens are retained out of 

 probably a large number of specimens which had been studied 

 l)y the original describer, and it by no means follows that the 

 one or two so-called original specimens which are retained 

 faithfully represent the author's idea. I know that this is the 

 case with DeGeer's collection at Stockholm, and I believe that 

 it is the case with many other old collections, so that the so- 

 called type may not truly represent the species described. 



The conclusion I arrive at is that all species must stand or 



