for Systematic Biology. 275 



I do not know who is the author of the saying, but systematic 

 work has been described as " the taking of snapshots at the pro- 

 cession of life." That is exactly my ideal, but I deny that our 

 ' species ' are snapshots at any procession of Nature. Let us by 

 all means snapshot the forms of life which come within our range 

 and leave it to future generations to arrange the ' procession ' as 

 our labour shall slowly reconstruct it. But when we place one 

 form called a ' type ' at the head, and trail others anyhow after 

 it as varieties, our " snapshot of the procession " becomes a ' fake ' 

 unpardonable in the domain of science. 



I can, however, understand a philosophical difficulty being 

 here thrown in my way. It is this. We cannot possibly deal 

 with all the finer shades of variation ; we have neither eyes to 

 see them nor instruments to measure, nor means to test their 

 value or to unravel the complexities of concomitant variations 

 in the more specialized organisms. We shall still have to ' lump ' 

 the forms together and our method will after all be the same as 

 that which is now adopted. While this may be verbally true, 

 for our most perfect method can only be an approximation, it is 

 practically false. I am contending that the doctrine of evolution 

 demands that we should take the varying forms assumed by living 

 organisms as the units of our classification. It is useless to say, 

 " But there are shades and complexity of variation which our 

 powers of observation are not exact enough to enable us to 

 appreciate." All we have to do is to describe and designate those 

 forms whose differences we can now appreciate. We do not really 

 know what powers of observation we may not acquire so soon as 

 we deliberately adopt this as our method of work. We already 

 distinguish forms which our forefathers ' lumped ' together and 

 our systematists are describing thousands of apparently new forms 

 almost every year, although unfortunately they continue to group 

 them blindly into genetic 'species' with their varieties, thereby 

 making assumptions which are not only useless but even seriously 

 impede progress. 



The different forms, then, which we can distinguish must be 

 our units, and we want a formula which will enable us to desig- 

 nate them. We need not be appalled at the idea of having to 

 try to group the almost infinite number of different forms assumed 

 by living matter into evolutionary series. For unless our collec- 

 tions are large enough to reveal to us series, we have nothing to 

 do but to record the forms and what little fragments of series we 



form as the type of a new " species" is universally denounced as a useless multi- 

 plication of "species." And yet if the "species" is to continue to be the unit of 

 work I cannot see what else a really conscientious worker can do. By conscientious 

 worker I mean one who will not guess, and lays no claim to having any special 

 " feeling " for species. 



