344 
ON CROSSES AND 
different state of soil or of atmosphere, produce a barren 
cross, while the most dissimilar, if they possess the same 
constitutional predilections, give birth to a fertile plant, can- 
not remain as an isolated circumstance, but must be consi- 
dered by every unprejudiced and philosophical mind with 
reference to the whole vegetable creation. I have lately 
heard it admitted in conversation by an eminent botanist, 
that he had almost arrived at the conviction that there was 
but one rose, meaning that there seemed to be no natural 
impediment to the fertile intercourse of the great variety of 
plants which constitute the known species of that extensive 
genus. Let it be observed, if the fact is so, the reason is 
apparent enough ; that, although some roses will endure a 
little more cold than others, there is a sameness of constitu- 
tion throughout the genus, which affects a dry soil and a 
temperate atmosphere. The genus Calceolaria embraces 
plants very dissimilar to the eye of the botanist, as well as of 
the unlearned observer, of which some are absolutely stem- 
less, and bear only leaves and flower- stalks, while others are 
shrubby, and acquire a strong woody stem some feet in 
height ; yet there appears to be no limit whatsoever to their 
intermixture, and their produce may be crossed again inde- 
finitely. Are we, then, to come to the result that there is 
but one Calceolaria, oversetting not only the nicer distinc- 
tions of botanical science, but the difference between herb and 
shrub? The African Gladioli, excepting those which, like 
the European, present their flowers in front of the stalk, have 
been intermixed by me without any difficulty occurring, and 
the crosses of the most dissimilar have proved abundantly 
fertile, and four or five sorts have been blended in successive 
generations. Some of the complicated crosses have pro- 
duced seed less freely, and one treble cross (Hirsuto-Cardi- 
nali-blandus) has as yet produced none that has vegetated, 
probably because the last male, G. hirsutus, is of a constitu- 
tion much less suited to our climate than the other two. Are 
we then to come to the result, that these dissimilar species 
are all one natural Gladiolus ? There is no outward sign of 
barrenness in G. hirsuto-Cardinali-blandus, which will pro- 
bably bear seed under favourable circumstances ; that there 
is no insurmountable natural impediment may be proved 
thus ; the offspring of G. versicolor by hirsutus, of blandus 
by versicolor, and of Cardinali-blandus by tristis, have all 
borne seed, shewing that G. hirsutus is not of a separate 
