334 



DARWINISM TO-DAY. 



the two theories is graphically shown. I translate here this 

 "parallel columns" statement in full : 



ACCORDING TO THE TRANSMUTA- 

 TION THEORY. 



1. To all organisms there be- 

 longs a capacity for variation 

 which is called into play partly 

 through inner, partly through 

 outer causes, through use and 

 disuse, etc. This capacity for 

 variation regularly finds its ex- 

 pression in the appearance of 

 slight and unnoticeable individ- 

 ual differences. 



2. As a result of this strug- 

 gle for existence and selection, 

 those individual variations 

 which prove themselves useful 

 become fixed and accumulated, 

 while the non-useful ones dis- 

 appear. All characteristics and 

 peculiarities of a species must, 

 as a result of a prolonged selec- 

 tion, stand in harmony with the 

 outer conditions, and be useful 

 to the organism. 



3. Through prolonged selec- 

 tion and accumulation of char- 

 acteristics all species undergo 

 a persistent change, whereby 

 they are gradually transformed 

 into new species without, how- 

 ever, sacrificing their normal 

 physiological relations. 



4. This process can take place 

 everywhere and under all cir- 

 cumstances. The harder the 

 outer conditions and the sharp- 

 er the struggle for existence, 

 the more energetically selection 

 works, and therewith the quick- 



ACCORDING TO THE THEORY OF 

 HETEROGENESIS. 



1. To all organisms there be- 

 longs a capacity for variation, 

 which is a fundamental inner 

 peculiarity independent of outer 

 conditions, and which remains 

 usually in latent condition, re- 

 tained by heredity, but which 

 now and then finds its expres- 

 sion in sudden changes. 



2. These sudden changes can, 

 under favourable conditions, be 

 the beginnings of persistent 

 races. These new characteris- 

 tics, having appeared independ- 

 ently of outer conditions, are 

 sometimes useful to the organ- 

 ism, but they may also stand in 

 no harmony with outer condi- 

 tions. 



3. All once-formed species re- 

 main unchanged, although new 

 forms occasionally split off from 

 them by heterogenesis. Such 

 newly-arisen forms have, as the 

 result of a disturbed heredity, a 

 deranged constitution, which re- 

 veals itself in a lessened fertility 

 and often in a generally weak- 

 ened condition of the organism. 

 The new forms, becoming con- 

 stant races, gradually recover 

 their constitution. 



4. The origin of new forms 

 can, however, occur only under 

 favourable conditions of exist- 

 ence for the species, and the 

 more favourable these condi- 

 tions, that is, the less severe 

 the struggle for existence, the 



