Mr. liic/ieno's Paper on Systons and Methods. 405 



the difficulties which appear to have beset you in the particular depait- 

 ment of Natural History which you have studied, but I may state that 

 when similar difficulties occur in Zoology, and species are ascertained 

 " to run into one another,'' we are accustomed to doubt the fact of their 

 being distinct species ; we call them varieties, and search for some gene- 

 ral characteristic which will include and insulate the whole of these va- 

 rieties, and then call that the specific character. If I may trust the 

 evidence of my eyes, the White and Negro races of the human species 

 " run into one another by imperceptible shades unappreciable by human 

 " sense, so as to render it impossible to circumscribe them." Nay, 

 there are " empirical characters" which distinguish even a Frenchman 

 from an Englishman, and " which can only be perceived by long and 

 *' familiar experience, and cannot be described by words ;" yet no one 

 hitherto has been bold enough to declare them distinct species. It seems, 

 nevertheless, that there are certain persons " who think it advisable to 

 " break up" the old species into many new ones, but you evidently 

 consider such persons as angels in comparison to the wretches who would 

 dare to subdivide a Linnean genus, a crime which you have ever held 

 in the utmost abhorrence. Yet, as I understand the matter, if there be 

 any groupe in Natural History more truly insulated than another, it is a 

 species, and the division of this natural groupe of individuals ought 

 scarcely, therefore, to be less blamed than that of a genus which may 

 have only rested on the good pleasure or ignorance of Linngeus, or on 

 that of some blind worshipper of his infallibility. Not indeed that 1 

 would have those poor species-makers attacked ; for I care very little one 

 way or the other about them, although for all that I know, even they 

 may be doing good in their generation, by pointing out differences. 



By the bye, on the subject of species you settle the question, by de 

 ciding that " in cases of difficulty the assumed law ought to be brought to 

 " the test of experiment, or the species should be rejected." Now I find 

 it to be a case of some difficulty to understand this advice, since on looking 

 back, the only " assumed law'^ I can perceive mentioned is as follows : 

 " A species shall be that distinct form originally so created, and pro- 

 " ducing, by certain laws of generation, others like itself," and unfor- 

 tunately you have forgotten to inform us how we are to ascertain by expe- 

 riment, " a distinct form originally so created." This, however, is 



