330 Extracts from Mr. Bentham’s Address. 
plified in Cassia itself, in which I have shown that no less than 
eight or nine different: modifications of type, sectional and sub- 
sectional, are common to South America, tropical Africa, and 
Australia, but without an _ panel or, at least, subspecific iden- 
my, except perhaps in a few cases where a more modern inter- 
ale rous and reducible to definite oups—large anil 
small well-marked genera in both countries, and yet not a sin- 
gle genus common to the two; not only the species, but the 
genera themselves have become geographical. As in the case 
of the varieties of Pelargonium and Nicotiana, so in that of the 
species of Cassia and of the genera of Proteacese, it is not to be 
ently combined, the changes in the organs are differently corre- 
lated. In Asiatico-African Chamecriste a tenden ney to a par- 
ticular change in the venation of the leaflet is accompanied by 
a certain change in the petiolar gland; in America the same 
change in the gland is correlated with a different alteration in 
the venation. In Australian Protéacex the glands of the torus 
are constantly deficient with a certain inflorescence (cones with 
imbricate scales) which is always accompanied by them in Africa. 
In selecting the above instance for illustration of what we 
may, without much strain upon the imagination, suppose to be 
. — | characters i in ‘different directions in the iifferent 
with regard to the succession of races which have undergone 
successive geological | 
we have not in plants, as far oi am aware, any such cases” of 
“true r types or forms which are intermediate between — 
others because they stand in a direct genetic relation to them, 
: os the Ho appears to have made out in favor of = ‘a 
ee OS ae ee ae eS Cee 
| 
