| Comparison with 1860 | 
  | 
namely, closeness of descent with various degrees of modification.  Nearly the same rules are followed in classifying varieties, as with 
species.  Authors have insisted on the necessity of classing 
varieties on a natural instead of an artificial system; we are cautioned, for instance, not to class two varieties of the pine-apple together, merely because their fruit, though the most important part, happens to be nearly identical; no one puts the 
 swedish | swedish 1859 1860 |  | Swedish 1861 1866 1869 1872 |  
  
and common turnips 
together, though the esculent and thickened stems are so similar.  Whatever part is found to be most constant, is used in classing varieties: thus the great agriculturist Marshall says the horns are very useful for this purpose with cattle, because they are less variable than the shape or colour of the body, &c.; whereas with sheep the horns are much less serviceable, because less constant.  In classing varieties, 
I apprehend 
 if | if 1859 1860 1861 |  | that if 1866 1869 1872 |  
  
we had a real pedigree, a genealogical classification would be universally preferred; 
and it has been attempted by 
some authors.  For we might feel sure, whether there had been more or less modification, the 
principle of inheritance would keep the forms together which were allied in the greatest number of points.  In tumbler pigeons, though some sub-varieties differ from the others 
in the important character of having a longer 
beak, yet all are kept together from having the common habit of tumbling; but the short-faced breed has nearly or quite lost this habit; 
nevertheless, without any reasoning or thinking 
on the subject, these tumblers are kept in the same group, because allied in blood and alike in some other respects.  If it could be proved that the Hottentot had descended from the Negro, I think he would be classed under the Negro group, however much he might differ in colour and other important characters from negroes. 
 | 
 
  
  
namely, closeness of descent with various degrees of modification.  Nearly the same rules are followed 
 in classifying varieties, as with | in classifying varieties, as with 1859 1860 1861 1866 |  
| as in classifying 1869 1872 |  
  
species.  Authors have insisted on the necessity of 
 classing | classing 1859 1860 1861 1866 |  | arranging 1869 1872 |  
  
varieties on a natural instead of an artificial system; we are cautioned, for instance, not to class two varieties of the pine-apple together, merely because their fruit, though the most important part, happens to be nearly identical; no one puts the 
 Swedish | Swedish 1861 1866 1869 1872 |  | swedish 1859 1860 |  
  
and common 
 turnips | turnips 1859 1860 1861 1866 1869 |  | turnip 1872 |  
  
together, though the esculent and thickened stems are so similar.  Whatever part is found to be most constant, is used in classing varieties: thus the great agriculturist Marshall says the horns are very useful for this purpose with cattle, because they are less variable than the shape or colour of the body, &c.; whereas with sheep the horns are much less serviceable, because less constant.  In classing 
 varieties, | varieties, 1859 1860 1861 1866 1869 |  | varieties; 1872 |  
  
I apprehend 
 that if | that if 1866 1869 1872 |  | if 1859 1860 1861 |  
  
we had a real pedigree, a genealogical classification would be universally 
 preferred; | preferred; 1859 1860 1861 1866 1872 |  | preferred: 1869 |  
  
and it has been attempted 
 by | by 1859 1860 1861 1866 |  | in 1869 1872 |  
  
some 
 authors. | authors. 1859 1860 1861 1866 |  | cases. 1869 1872 |  
   For we might feel sure, whether there had been more or less modification, 
 the | the 1859 1860 1861 1866 1869 |  | that the 1872 |  
  
principle of inheritance would keep the forms together which were allied in the greatest number of points.  In tumbler pigeons, though some 
 sub-varieties differ from the others | sub-varieties differ from the others 1859 1860 1861 1866 |  
| of the sub-varieties differ 1869 1872 |  
  
in the important character of 
 having a longer | having a longer 1859 1860 1861 1866 1869 |  
| the length of the 1872 |  
  
beak, yet all are kept together from having the common habit of tumbling; but the short-faced breed has nearly or quite lost this 
 habit; | habit; 1859 1860 1861 1866 1869 |  | habit: 1872 |  
  
nevertheless, without any 
 reasoning or thinking | reasoning or thinking 1859 1860 1861 1866 |  
| thought 1869 1872 |  
  
on the subject, these tumblers are kept in the same group, because allied in blood and alike in some other respects.  If it could be proved that the Hottentot had descended from the Negro, I think he would be classed under the Negro group, however much he might differ in colour and other important characters from negroes. 
 |