sasg ee 
Notice of Dr. Hooker’s Flora of New Zealand. 335 
other of the parents, when the offspring reverts to that specific 
type. Dr. Hooker justly remarks, that, 
“Asa general rule, the-genera most easily hybridized in gardens 
are not those in which the species present the greatest difficulties. 
how many of the latter were fertile, and for how many generations 
they were propagated. The most satisfactory proof we can adduce, of 
Sextial, eir progeny is most likely to be originated from 
the conjunction of different trees, and individual peculiarities must 
thereby blended and obliterated. we consider 
or pine forest are fertilized by the pollen of another; when we 
take into view the great number of unisexual plants, and consider 
nature for limiting congenital or induced individual forms than 
Would at first appear. ‘That some such controlling or amalga- 
Mating agencies operate in nature may be inferred from a com- 
Patison of the general homogeneity of an indigenous species, over 
ven a large area, with the ready development of marked varie- 
'€S or races in the case of every cultivated plant which is mul- 
tiplied from seed, and their perpetuation from generation to gen- 
eration, which is almost always ensured merely by ene 
that an isolated race retains certain characteristics so long as kept 
Sparate is no proof that it constitutes a species. Many a variety 
Whatever individuals, however distinguished by minor differences — 
en separate, are found to blend into a fertile race when associ- 
ated, must on sound principles be regarded as belonging to one 
Species, Perhaps if zoologists would contemplate the wide varia- 
