( 495 ) 



spoiled in this way, leaving them, in the good old fashion of Linnean times, 

 without indication of the special localit}', etc., on which the modern stickler 

 for accuracy lays so much stress. Ami we are again well aware that a great 

 many sjiecies have been and are being baptised for tlie sake of the pleasure 

 the authors derive from the baptism. We do not grudge them either the honour 

 or the enjoyment ; they are legitimate. But an author must not claim that to 

 be the ultimate aim of systematic work, tliongh it may remain, with honour, 

 the Ultima Thule for many a describer of species. Every author may restrict 

 his work as he likes, but he must not put this restriction on science. The 

 extraneous barriers to the progress of science have fallen long ago. Members of 

 the scientific world ought not to erect barriers again ; they should not try to push 

 their own branch of science back into such narrow limits of thought and method 

 of research as science could be content with in the second half of the eighteenth 

 and the first half of the nineteenth century. Water and air are no longer 

 " elements " in physics and chemistry. Describing conspicuously diflferent species 

 and putting them somehow together is no longer the sole object of systematists. 

 Ask the scientist to leave off searching minutely and laboriously for all the 

 components of the air ; tell him that it is quite sufficient to know that the air 

 is comjiosed of nitrogen, o.xygen, and some carbonic acid. Perhaps he will 

 answer that the knowledge which satisfied him when he was a schoolboy does 

 not satisfy him now ; perhaps he will only laugh ; perhaps he will not even 

 do that. 



A systematist may narrow down his work to the standpoint of the older 

 writers on classification and not go beyond describing and classifying what is 

 different enough to be easily distingnished. We readily concede that. But we 

 also see that this " conspicuist " is very much mistaken if he believes himself 

 to be out of all difficnlties. As soon as he attempts to be critical, he will get 

 into a rare muddle. The non-recognition of non-conspicnons geographical varieties 

 — these varieties being the thorn in the eyes of the conspicnists — carries with 

 it the necessity of sinking as synonyms the names of all those non-conspicuous 

 geograpliical varieties (= subspecies) which have been recognised by other 

 authors, and consequently also the necessity of distingnishing between what 

 is conspicuonsly different and what is not. Now, it is a matter of common 

 knowledge that it is impossible to agree about what is and what is not 

 conspicuous. If onlj' one or a few specimens of two forms are at our disposal, 

 the difference may ai)pear slight, while it impresses itself more strongly on 

 the eye if a loug series is compared side by side. Differences in bright colours 

 are more easily noticed than differences in sombre colours. To a trained eye 

 a distinction will appear conspicuous for which an untrained eye looks in vain. 

 An author who employs only the naked eye or at the highest a weak lens, and 

 consequently sees many characters only very dimly, naturally does not perceive 

 the distinctions hidden under the surface in the same bright light as the author 

 who employs a stronger magnifying power. After swimming on the surface 

 one should learn diving. A differential character grows in conspicuousness 

 the longer an author works at the respective group of species — that is to say, 

 the more familiar the authcn- becomes with it. A small distinction, which is 

 apparently quite insignificant, grows at once in the mind of tlio scientist to 

 a conspicuous distinction, when discovered to be of higli significance as a 

 diagnostic character. A doctor who has little experience in o[ihthalniic matters 



