192 EVOLUTION AND DOGMA. 



that the species is wild, or is such as it appears in 

 nature." l 



Nothing could better illustrate the uncertain 

 character of species and the impossibility of distin- 

 guishing species from varieties, or one species from 

 another species, even when they are widely diverg- 

 ent, than certain experiments made some years ago 

 by a Russian naturalist, Schmankewitsch, upon a 

 species of crustacean known as artemia Miihlhaus- 

 enii. Normally, this organism lives in water which 

 is slightly saline. By increasing the salinity of the 

 water, this experimenter was enabled to transform 

 the species in question into an entirely different 

 one, artemia salina. Reversing the process, the 

 original species was obtained. But this was not all. 

 By continuing to diminish the amount of salt in the 

 water, a species was finally obtained that was so 

 entirely different from the original one, that it had 

 previously been regarded as belonging to a distinct 

 genus, branchippus. The changes mentioned took 

 place slowly, the complete transformation being 

 effected only after several generations. And all the 

 types here referred to as having been artificially pro- 

 duced, were known before, and had always been 

 considered as distinct species and genera. Now, 

 however, that their genetic relationship has been 

 demonstrated, anti-transformists assert that all the 

 three forms spoken of are but varieties of one and 

 the same species. And so they must assert, for 



1 Cf. contribution " On the Osteology of the Chimpanzees 

 and Orangs," in the Transactions of the Zoological Societies 

 for 1858. 



