| Comparison with 1869 | 
| 
 | 
| and assuming a separate act of creation. ↑ It is certain that many forms, considered by highly-competent judges as varieties, so completely resemble species in character, that they have been thus ranked by other highly-competent judges.  But to discuss whether 
 they ought to be| 1 blocks not present in  1859 1860 1861 1869; present in  1866 1872 |  | It cannot, however, be disputed 
that many forms, considered by highly-competent judges as varieties, have so perfectly the character of species 
that they have been ranked 
by other highly-competent judges 
as  good  and  true  species. | 
called species or varieties, before any definition of these terms has been generally accepted, is vainly to beat the air.| they ought to be 1869 1872 |  | such slightly different forms are rightly 1866 | 
 | 
|  | 
| Many of the cases of strongly-marked varieties or doubtful species well deserve consideration; for several interesting lines of argument, from geographical distribution, analogical variation, hybridism, &c., have been brought to bear on 
the attempt to determine their rank.  Close investigation, in many cases, will bring 
naturalists to an agreement 
how to rank doubtful forms.  Yet it must be confessed that 
 it 
is in the best known countries that we find the greatest number of forms of doubtful value.  I have been struck with the fact, that if any animal or plant in a state of nature be highly useful to man, or from any cause closely attract 
his attention, varieties of it will almost universally be found recorded.  These varieties, moreover, will often be ranked by some authors as species.  Look at the common oak, how closely it has been studied; yet a German author makes more than a dozen species out of forms, which are almost universally considered as 
varieties; and in this country the highest botanical authorities and practical men can be quoted to show that the sessile and pedunculated oaks are either good and distinct species or mere varieties. ↑ | 4 blocks not present in  1866 1869 1872; present in  1859 1860 1861 |  | I will here give only a single instance,— the well-known one of the primrose and cowslip, or Primula veris 
and elatior.  
These plants differ considerably in appearance; they have a different flavour 
and emit a different odour; they flower at slightly different periods; they grow in somewhat different stations; they ascend mountains to different heights; they have different geographical ranges; and lastly, according to very numerous experiments made during several years by that most careful observer Gärtner, they can be crossed only with much difficulty. 
We could hardly wish for better evidence of the two forms being specifically distinct. 
On the other hand, they are united by many intermediate links, and it is very doubtful whether these links are hybrids; and there is, as it seems to me, an overwhelming 
amount of experimental evidence, showing that they descend from common parents, and consequently must be ranked as varieties. | 
 | 
|  | 
| I may here allude to a remarkable memoir lately published by A. de Candolle, on the oaks of the whole world.  No one ever had more ample materials for the | 
 
  
  
| and assuming a separate act of creation.  It 
 cannot, however, be disputed that many forms, considered by highly-competent judges 
 as varieties, have so perfectly the character of species| cannot, however, be disputed 1866 |  | is certain 1872 | 
that they have been 
 ranked| as varieties, have so perfectly the character of species 1866 |  | to be varieties, resemble species so completely in character, 1872 | 
by other highly-competent 
 judges 
 as 
 good 
 and 
 true 
 species.| ranked 1866 |  | thus ranked 1872 | 
↑| species. 1866 |  | species.1872 | 
But to discuss whether 
 such slightly different forms are rightly| 1 blocks not present in  1859 1860 1861 1866 1872; present in  1869 |  | It is certain that many forms, considered by highly-competent judges as varieties, so completely resemble species in character, that they have been thus ranked by other highly-competent judges. | 
called species or varieties, before any definition of these terms has been generally accepted, is vainly to beat the air.| such slightly different forms are rightly 1866 |  | they ought to be 1869 1872 | 
 | 
|  | 
| Many of the cases of strongly-marked varieties or doubtful species well deserve consideration; for several interesting lines of argument, from geographical distribution, analogical variation, hybridism, &c., have been brought to bear 
 on the attempt to determine their 
 rank; but space does not here permit me to discuss them.| on 1859 1860 1861 1866 1869 |  | in 1872 | 
Close investigation, in many cases, will 
 bring| rank; but space does not here permit me to discuss them. 1866 1869 1872 |  | rank. 1859 1860 1861 | 
naturalists to 
 an agreement| bring 1866 1869 |  | no doubt bring 1872 | 
how to rank doubtful forms.  Yet it must be confessed that 
 it, 
is in the best known countries that we find the greatest number of 
 forms of doubtful value.| an agreement 1866 1869 |  | agree 1872 | 
I have been struck with the fact, that if any animal or plant in a state of nature be highly useful to man, or from any cause closely 
 attract| forms of doubtful value. 1866 1869 |  | them. 1872 | 
his attention, varieties of it will almost universally be found recorded.  These varieties, moreover, will often be ranked by some authors as species.  Look at the common oak, how closely it has been studied; yet a German author makes more than a dozen species out of forms, which are almost universally considered 
 as| attract 1866 1869 |  | attracts 1872 | 
varieties; and in this country the highest botanical authorities and practical men can be quoted to show that the sessile and pedunculated oaks are either good and distinct species or mere varieties.| as 1866 1869 |  | by other botanists to be 1872 | 
 | 
|  | 
| I may here allude to a remarkable memoir lately published by A. de Candolle, on the oaks of the whole world.  No one ever had more ample materials for the |