| Comparison with 1861 | 
| 
 | 
| other; but only a single head produced any seed, and this one head produced only five grains.  Manipulation in this 
 ease could not have been injurious, as the plants have separated sexes.  No one, I believe, has suspected that these varieties of maize are distinct species; and it is important to notice that the hybrid plants thus raised were themselves 
perfectly 
fertile; so that even Gärtner did not venture to consider the two varieties as specifically distinct.| ease 1861 |  | case 1859 1860 1866 1869 1872 | 
 | 
|  | 
| Girou de Buzareingues crossed three varieties of gourd, which like the maize has separated sexes, and he asserts that their mutual fertilisation is by so much the less easy as their differences are greater.  How far these experiments may be trusted, I know not; but the forms experimentised 
on, 
are ranked by 
 Sagaret, who mainly founds his classification by the test of infertility, as 
 varieties.| Sagaret, 1859 1860 1861 |  | Sageret, 1866 1869 1872 | 
| varieties. 1859 1860 1861 |  | varieties, and Naudin has come to the same conclusion. 1866 1869 1872 | 
 | 
|  | 
| The following case is far more remarkable, and seems at first 
 quite incredible; but it is the result of an astonishing number of experiments made during many years on nine species of Verbascum, by so good an observer and so hostile a witness, 
as Gärtner: 
 namely,| quite 1859 1860 1861 1866 1869 |  | quite1872 | 
that 
 yellow| namely, 1859 1860 1861 1866 1869 |  | namely 1872 | 
and white varieties 
 of the same species of Verbascum when| yellow 1859 1860 1861 1866 |  | the yellow 1869 1872 | 
intercrossed| of the same species of Verbascum when 1859 1860 1861 1866 |  | OMIT 1869 1872 | 
produce less 
 seed,| intercrossed 1859 1860 1861 1866 |  | when crossed 1869 1872 | 
than 
 do either| seed, 1859 1860 1861 1866 |  | seed 1869 1872 | 
coloured varieties 
 when fertilised with pollen from their own coloured flowers.| do either 1859 1860 1861 |  | does either 1866 |  | the similarly 1869 1872 | 
Moreover, he asserts 
 that| when fertilised with pollen from their own coloured flowers. 1859 1860 1861 |  | when fertilised with pollen from its own coloured flowers. 1866 |  | of the same species. 1869 1872 | 
when yellow and white varieties of one species are crossed with yellow and white varieties of a 
distinct 
species, more seed is produced by the crosses between the same 
coloured flowers, than between those which are differently coloured. ↑| that 1859 1860 1861 |  | that, 1866 1869 1872 | 
Yet these varieties 
 of Verbascum present no other difference besides the mere| 1 blocks not present in  1859 1860 1861 1866; present in  1869 1872 |  | Mr. Scott, 
also, 
has experimented on the species and varieties of Verbascum; and although unable to confirm Gärtners 
results on the crossing of the distinct species, he finds that the dissimilarly coloured varieties of the same species yield fewer seeds, in the proportion of 86 to 100, than the similarly coloured varieties. | 
colour of 
 the| of Verbascum present no other difference besides the mere 1859 1860 1861 1866 |  | differ in no respect except in the 1869 1872 | 
flower;| the 1859 1860 1861 1866 |  | their 1869 1872 | 
and one variety can sometimes be raised from the seed of 
 the| flower; 1859 1860 1861 1866 |  | flowers; 1869 1872 | 
other.| the 1859 1860 1861 1866 |  | the1869 1872 | 
| other. 1859 1860 1861 1866 |  | another. 1869 1872 | 
 | 
|  | 
| From observations 
which I have made on certain varieties of hollyhock, I am inclined to suspect that they present analogous facts. | 
|  | 
| Kölreuter, whose accuracy has been confirmed by every subsequent observer, has proved the remarkable fact, that one 
 variety of the common tobacco 
 is| variety 1859 1860 1861 1866 |  | particular variety 1869 1872 | 
more 
 fertile,| is 1859 1860 1861 1866 |  | was 1869 1872 | 
when| fertile, 1859 1860 1861 1866 |  | fertile 1869 1872 | 
crossed with a widely distinct 
 species,| when 1859 1860 1861 1866 |  | than the other varieties, when 1869 1872 | 
than| species, 1859 1860 1861 1866 |  | species. 1869 1872 | 
are| than 1859 1860 1861 1866 |  | than1869 1872 | 
the| are 1859 1860 1861 1866 |  | are1869 1872 | 
other| the 1859 1860 1861 1866 |  | the1869 1872 | 
varieties.| other 1859 1860 1861 1866 |  | other1869 1872 | 
He experimentised 
on five 
 forms,| varieties. 1859 1860 1861 1866 |  | varieties.1869 1872 | 
which are commonly reputed to be varieties, and which he tested by the severest trial, namely, by reciprocal crosses, and he found their mongrel offspring perfectly fertile.  But one of these five varieties, when used either as 
 father| forms, 1859 1860 1861 1866 1869 |  | forms 1872 | 
or mother, and crossed with the Nicotiana glutinosa, always yielded hybrids not so sterile as those which were produced from the four other varieties when crossed with N. 
 glutinosa. Hence the reproductive system of this one variety must have been in some manner and in some degree modified.| father 1859 1860 1861 1866 |  | the father 1869 1872 | 
| glutinosa. Hence the reproductive system of this one variety must have been in some manner and in some degree modified. 1861 |  | glutinosa. 1859 1860 1866 1869 1872 | 
 | 
| Text in this page (from  paragraph 4000, sentence 400 to  paragraph 4000, sentence 400, word 4) is not present in 1861 |