51 



unimportant, betrays the hidden l:)ond of community of descent. Let 

 two forms have not a sint^le character in common, yet if these extreme 

 forms are connected tog-ether by a chain of intermediate groups, we 

 may at once infer their community of descent, and we put them all 

 into the same class." (Origin of Species, p. 426) Therefore, if we 

 have two forms of the same genus, but without a single specific char- 

 acter in common, and these two forms are connected by intermediate 

 forms, we at once infer their community of specific (not generic) de- 

 scent and varietal modification, and we class them as the same species. 



There are many instances in nature. Among the snakes, for exam- 

 ple, in the genus Op/u'bolns, Prof Cope has shown that two forms, — 

 one Northern, the other Southern, for a time considered distinct, ^ — ^have 

 been found to grade directly into each other, and therefore are but va- 

 rieties of the same species. He has not insisted that they were distinct 

 species, as Mr. Edwards would have done, and then justified himself 

 on the ground of reversion of character. Nor would Prof Cope have 

 called every intermediate form a distinct species merely because their 

 young might differ from other young forms. 



Referring to the closely related but geographically separated species 

 of plants, quoted by Dr. Gray, Mr. Edwards says: " I do not find, 

 by the way, that Dr. Gray gives these related forms any less rank than 

 species." Of course not, for there are absolute constant specific char- 

 acters to separate them, otherwise Dr. Gray would have called them 

 all varieties of one species, for wide geographical separation is not 

 alone a specific character. Why does not Mr. Edwards call every 

 marked variety a species, and the ancestral specific type from which 

 it springs a genus, for by his reasoning it must be so. Look at the so- 

 called dififerent species allied to Papilio Asterias, viz. : Indra, Brcvi- 

 ca7ida,Bairdn, etc. If these forms are all distinct — and it is plain to 

 see that they all sprung from one immediate progenitor very dififerent, 

 for instance, from the ancestral type of the Tiiryuis group — then they 

 should be classed as a distinct genus by themselves, for it is evident 

 that they possess an aggregate of characters that will proclaim their 

 community of origin. May we not better call all these forms but the 

 \arietics of some one form, say Asterias, and infer that the characters 

 descending from the immediate ancestral type are only specific ? I 

 think this illustration may serve to show the absurdity of calling every 

 slight variation a new species. 



The above consideraticjns may prepare us for a brief criticism ol 

 the methods by which certain naturalists rush into the publication of 

 new species. Mr. Edwards has said: "If, in my opinion, a form of 

 butterfly of which nothing is known except by the dried specimens, is 

 distinct enough to deserve a specific name, I give the name without 

 hesitation." In another place he adds: "I spot the new form, make it 

 conspicuous, place it where it can not be overlooked, and leave it to time 



