cl 
J. D. Hooker, Introductory Essay to the Flora of Tasmania. 9 
Now my object in dwelling on this parallelism between the 
characteristics of gecerrs. 9 in relation to species, of species in 
relation to genera, and of genera in relation to orders, is because 
I consider (Introd. ie to Fl, N. Z.) that it is to the extinction 
of species and genera that we are indebted for our means of re- 
solving plants into limitable genera and orders, This view is 
now, I believe, generally admitted, even by those who still re- 
ard species as the immutable units of the vegetable creation ; 
and it therefore now remains to be seen how far we are warrante 
exis 
~ 
* It follows asa coroll ) proposition (that species, ete, are naturally 
rendered rasa ee by | the det of varieties), that there must ee some inti- 
stroyed, and that the birth of individuals and the production of new forms is wa 
ceeding at a gr renter proportional rate than in an equally large genus of which the 
saa are limitab 
+ My friend Mr, “Wallace treats of animals under domestication, iy only as if 
i ‘om t of nature, inas- 
were in very different physical conditions from i 
much e and faculty is continually fully amore ona by 
wild animals, whilst certain o ie do in th ted, but as if 
they were subject to a wagtarorns of ee laws. He sz No 
infer 0 variet a state of nature can edue the atio 
of occurrin, a ic animals, e two are so much opposed that 
what applies to a ae is almost sure not to apply to the other But, i t 
place, of the cies of wild anima - ilies must aced where cer- 
tain facul - more exe _ others, and the diff n 
3 ——— between the condition a er a veudlies of wild ani is as great as 
n many wild and ta er stones and fi 
; and secondly, 
tice iaient and unknown in the wild et but which are as proper to the spécies 
as any it exercised in its Mats of 3 are pee or cae ae oped by it rane domes- 
ication. pe cet to organs 
ae: ts! a SE ney of A oer it wi 
t ina a wild condition J i 
for nan cannot ok the order of nature, though he e may hi A008. Rahaneh scam Sf 
"cone SERIES, Vor XXIX, No, 85,—JAN., 1860. é 
Qe : 
