44 FOOT-NOTES TO EVOLUTION. 



century has been largely wasted. Which of the forms we 



study are species, and therefore represent separate acts 



of the Creator, and which are mere varieties, chance 



^^ ,. , products of varying surroundings, and 

 The reahty of ^l , , , . . , . 



species. therefore to be despised and ignored ? 



Scarcely ever did two earnest students 

 of any group reach an agreement as to this question, for 

 agreement is only possible when material is lacking. A 

 single additional specimen often unsettles every conclu- 

 sion, and the contents of all the museums are but the 

 slightest fragment of the life of the globe. " We can 

 only predicate and define species at all," says Dr. Coues, 

 "from the mere circumstance of missing links. Our 

 species are twigs of a tree separated from the parent 

 stem. We name and arrange them arbitrarily in default 

 of means of reconstructing the whole tree in accordance 

 with Nature's ramifications." Among Dareste's eels we 

 may have one species, or four, or forty, as our collection 

 may be deficient in connecting forms, or as we may 

 choose to magnify or disregard slight differences. There 

 are just as many kinds of eels as there are races of men 

 or of dogs. Future naturalists will again describe those 

 eels; but they will know them for what they are— the 

 varying descendants of some one degenerated type of 

 fishes, crawling in the weeds and ooze of many seas 

 and rivers, and thus variously modified by their sur- 

 roundings. 



Meanwhile the old notion of a species has passed 

 away forever. We can no more return to it than as- 

 tronomers can return to the Ptolemaic 

 The old idea of , • r ^u i r,,, 



. , notion of the solar system. The same 



species has ^ 



passed away. lesson comes up from every hand. It is 



the common experience of all students 



of species. I do not know of a single naturalist in the 



world who has made a thoughtful study of the relations 



