SPECIES ATnD SrESPEClES. 233 



divides the genus Erophila into two sections), tlie amount of pubes- 

 cence, tlie shape of the pod, the shape, size and colour of the 

 leaves, the size and colour of the flowers, and the general habit. 

 The number of species of Erophila in France, he believes to be 

 at least twice as many as those to which he has already given 

 names, and if we consider the wide range of JE. verna from 

 temperate North America to the Himalayas, and its extreme abun- 

 dance throughout the whole of its range, in the old world at least, 

 we may fairly infer that with proper opportunities of observation 

 the number of species would amount to at least two hundred. It is 

 interesting to note the fact that these supposed species are all local 

 forms. Not more than three or four of the fifty-three are usually 

 found growing intermixed, and very frequently millions of individuals 

 of a single form are found growing together without intermixture 

 of a single specimen of any of the others. Each year too the same 

 forms re-appear in the same places absolutely unchanged in 

 character. 



What then do we learn from M. Jordan's observations ? We 

 think that they may be considered to establish the fact that a 

 practised observer can divide the assemblages of individuals commonly 

 considered as species (using that word in the widest of the senses in 

 which it is employed), into a greater or less number of forms to 

 which definite characters can be given. These forms can, under 

 favourable circumstances, be recognised with facility in a growing 

 state, less certainly and often doubtfully in a dried state. In some 

 cases, at least, they transmit their characters unaltered to their oif- 

 spring during a certain number of years. The existence of these 

 differences does not imply their permanence, nor does the trans- 

 mission of slight characters by descent during a few generations 

 prove that such characters will never vary. AVhether, with M. 

 Jordan, we call these distinct forms species, or with most other 

 naturalists, races, depends on theoretical considerations which every 

 naturalist must work out for himself, and on which, as is w^ell known, 

 there are at the present time the greatest possible difterences of 

 opinion. 



Though M. Jordan is, as we have seen, fully convinced that 

 these slightly distinct forms are permanent, and are therefore rightly 

 regarded as species and adinitted into our Eloras, he does not, on 

 that account, the less recognise the existence of the old species 

 of which they are fractional parts, as distinct entities, to use a 



N.H.R.— 1865. R 



