BENTHAM ON THE SPECIES AND GENERA OF PLANTS. 143 



whether it be a distinct species or a mere variety, the points to be con- 

 sidered, independently of direct experiment, will be chiefly the follow- 

 ing :— 



Are the distinctive characters such as can be accounted for by 

 station, climate, or other known influences, of which I have enumerated 

 several in my Handbook ? (Introd. p. 31 and 32.) 



Are the circumstances under which it was growing, and its general 

 aspect, such as to suggest its being a hybrid between the allied and some 

 other species ? 



Are the distinctive characters such as are known to occur in mere 

 varieties of other species, more especially of such as are systematically 

 allied to the one in question ? 



Is the plant in question, an isolated individual (including in the same 

 category any number of individuals naturally propagated from a single 

 one by runners, suckers, bulbs, &c); or has it been observed in more or 

 less abundance in any variety of stations over any considerable inde- 

 pendent geographical area, or in any important part of the area of the 

 allied species ? 



Is the distinctive character relied on confined to a single organ, or is 

 it more or less accompanied by differences in other organs of the plant ; 

 and, if so, how far does the plant retain all the characters in all the dif- 

 ferent stations and localities where it has been observed ? 



Have intermediates between the plant and its allied species been 

 sought for in any considerable portion of the area of the latter, and espe- 

 cially in those countries where it is most liable to variations ? And, if 

 such intermediates exist, what is their relative number, and how far do 

 they vary, or pass one into another in all, or any, and which, of the 

 points in which the plant in question differs from its allied species ? 



It is only in proportion as the evidence on all these points is full, satis- 

 factory, and reliable, that our decisions on the value of a species can be 

 fair, independently of any want of tact, experience, powers of observa- 

 tion or judgment, which we are all liable to; and not to mention the 

 cases of but too frequent occurrence where ignorance, a false pride, va- 

 nity, a love of controversy, a desire of flattering, or even mercenary 

 motives, have influenced the reckless splitting or over-hasty reunion of 

 species. 



With regard to direct experiment in aid of inductive reasoning, it 

 has been said that cultivation is a sure and easy test of the identity or 

 distinctness of species ; and nothing is more common than to find as an 

 argument in support of a " critical" species, that it has been growing 

 for many years in a garden, always retaining its distinctive characters. 



for every 99,999 that perish either as seeds or young plants. It is often very curious 

 to observe the luxuriant crops of crowded seedlings of various plants in autumn, which 

 totally disappear before the following flowering season ; and year after year, an attentive 

 examination of the moors and heaths in many parts of Western England will disclose 

 a profusion of seedling oaks, one, two, or three years old, not one of which ever attains 

 the size and age even of a bush. 



