( 454 ) 



are called P. philolaus niger. The individuals of P. machaon with two black dots 

 on the forewing above between veins 6 and 8 are correctly treated in II. p. 26 as 

 aberration ; p. 26 as " Abart," P. machaon bimaculatas. The North African spring 

 brood of P. podaliriush, called " Abart " P. podalirius feistkameli, the samnier brood 

 " Abart " P. jjodulirius latteri, etc. By thus calling the same form here '' Abart " 

 and there " aberration," or even " species," and by using the same terminology for 

 aberrations, seasonal forms, and geographical races (P. podalirius undecimlineatus, 

 P. podalirius latteri, P. podalirius tiryatus; P. machaon bimaculatus, P. viachaon 

 asiaticus [= sikkitnensis'\),\iK certainly not proved that aberrational and sabspecific 

 characters are the same. Geographically separate races are entirely different from 

 aberrations, seasonal forms, and forms of dimorj)hic species that occur in the same 

 locality. A comi)arison of the variation of difi'erent organs, for instance of wing- 

 patterns and copulatory organs, reveals that at once. The combination of distiu- 

 gnishing characters of aberrations and seasonal forms is different from the com- 

 bination of distinguishing characters in geographical races as shown in Nov. Zool. 

 III. 1896. pp. 499 — 501. And this diversity in the combination of the characters 

 that constitute an aberration, or a seasonal form, from the combination of characters 

 that constitute a geographical race, shows clearly tliat correlation — so often advanced 

 in Artiildung as an important factor in the ramification of species — has little to do 

 with the origin of geographical races. That the latter are of the highest importance 

 in the divarication of species, tliat they are the true subspecies, forms in the process 

 of being evolved into new species, is proved by the great difference in the physiology 

 of the two kinds of varieties. For the offspring of an intercrossing between well- 

 marked al)errations of a species are not intermediate in characters between the 

 parents, but belong either to the one or to the other aberrational form, while the 

 offspring produced by an intercrossing between geographical races are, as in the 

 case of an intercrossing between different species, intermediate between the two 

 parent races. 



We know that individual aberrations are often confined to a certain portion of 

 the area of the respective species, that in other cases the aberrational characters 

 appear regularly in a greater number of individuals of a locality, and that in 

 others again all the individuals of that district possess certain distinguishing 

 characters (compare Nov. Zool. III. 1896. p. 477). The development of geo- 

 graphical individual aberrations leads to geographical races; the development of 

 non-geographical aberrations leads to dimorphism. Now, as the combination of 

 physiological — such as relate to propagation — and morphological characters in 

 marked non-geographical forms is different from that in marked geographical 

 forms, we must conclude that the two forms are difi'erent in kind in so far as factors 

 come into play in the evolution of geographical races which do not act in the case 

 of non-geographical forms of a species, and that we have, therefore, to distinguish 

 between causes of " aberrational " characters and causes of " subspecific " characters. 

 And as the combination of physiological — as shown by crossing — and morphological 

 characters is in geographical races tJie same as, but to a lower degree than, in sj)ecies, 

 it is obvious that the causes upon which depend the evolution of subspecies, = geo- 

 graphical races, are the same which lead to tlie origin of new species. 



In conclusion of this review, which I am sorry to say is mostly destructive, I 

 will not omit to point out that Elmer's researches on Lepidoptera, though full of 

 errors re facts and loose in argumentation, are nevertheless of great interest for the 

 classifier as well as llie general biologist. For the very boldness in language with 



