( 432 ) 



the very last we thiuk of in systematic work is that the form we now receive from a 

 particular locality has actually changed during the last fifty or two hundred years. 

 Of course, oiu' knowledge of a single specimen of a certain form preserved from the 

 collections made during tiie last century, and our knowledge of an old figure of that 

 form, does not enable us to draw any conclusions as to the extent of variation of that 

 form at the time of its capture, nor does such i)oor knowledge admit any conclusion as 

 to a probable transformation. The evidence is gone, and that is very much to be 

 regretted.* But should not the want of evidence from the past be a hint to us to 

 procure more evidence for the scientists who come after us ? It is all important to 

 j)rove that tlie transmutation of species upon which the theory of evolution is based 

 actually takes place ; and it would be a good object for small prorincial museums to 

 preserve long series of specimens, with exact dates, at least of the species of those 

 families of the respective district which are known to be easily influenced by the 

 transmutating factors, families which moreover are easily preserved, such as butter- 

 flies and moths, wingless beetles, and landshells ; museums with such collections 

 wotild not be simply a sight for the public, but they would be of scientific value, 

 and their scientific success would be far superior to that which they can obtain by 

 gathering sjiarse material from all countries of the globe. There would certainlv be 

 no want of voluntary help from the side of private collectors in civilised countries. 

 The study of the local fauna and flora and their variation carried out in this sense, 

 though many systematists and species-makers (which terms are not always syn- 

 onymous) look down upon the study of aberi-ations as being unscientific, stands far 

 above the mere descriptions of new species, which mostly do not help the least to 

 solve the all-governing questions of evolution, but add simply some more "species" 

 to the hundreds of thousands of " species " already made known. 



However, we are not entirely left wnthout evidence that transformation is 

 actually going on under our eyes. We know from many plants f and a small 

 number of animals that geographical races, when reared under conditions other than 

 those of the country where the race lives, change in characters ; we refer to the Porto 

 Santo rabbits.J and Poh/ommatus phlnens,^ and Pieris brnssicae. I And a striking 



' Since the above was written I h.ivc received Oberthiir's Etuili:i d^ EntomologU XX. lS9(i. Here 

 Oberthiir tries to demonstrate from copies of old figures of Lepidoptna ami figures of recently caught specimens 

 that no change has taken place in these insects since Linml^'s time. The differences, however, which are 

 exhibited by these old drawings ,ind the figures of the refent specimens are nt)t only so conspicuous that 

 identity is entirely out of the question, but the differences arc such that if they actually were found in  

 contemporary specimens, many prominent I.epidopterists, including Mr. Ch. Oberthiir himself, would tieat 

 these differences as being of '• specific " value. In fact, Clerck's figure of Papilio deiphohux resembles much 

 more that insect which Felder separated as a distinct species (Papilio driphontes) than it docs Oberthiir's 

 figure of a sixjcimen of detphohttx caught in lSi»3, Oberthiir must have been led by that kind of reasoning 

 indicated in the above text, el.se he could not have spoken of a ''proof" that the species in question have 

 not undergone " the least modification." This kind of reasoning is : first the figures of Clerck are mentally 

 corrected according to the characters of recent specimens, then the characters thus corrected are 

 pronounced to be identical with those of recent specimens. 



I by no means will say that the particular species in question have been transformed since Linni's 

 time ; but I maintain that if there is any evidence as to transformation or non-transformation, the 

 evidence is certainly in favour of transformation. 



t Kerner, Oute und gehlechU Arten, gives many illustrations of the transformation of plants. 



J Darwin. Variation of Animalx and Plants under Domrstictttioit. 2nd edition, London, 1888. p. III). 



§ VVeismann. Shidien in the Thiory of Descent. From pupae of the southern form of Polijommatut 

 phlaeaA brought from Italy to Germany imagines emerged which were intermediate between the Italian 

 and German forms. 



II Scndder. Hiitterflie/i of Mw Englaml II. 1S89. p. 1175, gives a detailed account of the gradual 

 spread of Pierui rapae, which butterfly was first noticcil in Canada in 18G0. and describes a new variety 

 (jiovanejliae^ into which rapae has developed. 



