482 MR, G. BENTHAM ON COMPOSITA. 
constitution, habit, or external circumstances, start into new life. 
Young progressive races, which, like the vigorous young indivi- 
duals which we see rise from the rotten remains of an aged plane, 
or olive, or fig-tree, may be rising before our eyes from some 
branch of an old race which has passed its prime, or whose 
origin may already be so remote as to be concealed from us. 
These young progressive races will be very prolific, ready colo- 
nizers; and their subordinate races will be generally numerous 
and so blended together as to defy all positive determination 
of their limits, and be variously estimated as subgenera, sec- 
tions, species, subspecies, or varieties. Most of the Cichoria- 
ceous genera may perhaps in this respect be considered as less 
ancient than most other tribes and still in a state of progress. 
The six Asteroid types above mentioned and the subtribe Gna- 
phatiew of Inuloidez may perhaps be regarded as races still 
vigorous, but breaking up into subordinate races of a local cha- 
racter, many of which already give indications of future diminu- 
tion and extinction, but some of which, as yet of a very low 
grade, exhibit a great susceptibility of extension and progress. 
Some confirmation of the hypothesis that some of the oldest of 
the primary or tribual and subtribual types of Composite are to 
be sought for in Helianthoides, and some of the most recent (of 
those dating from geological periods antecedent to the present 
one) among Cichoriaees, may perhaps be derived from their struc- 
ture. The great consolidation and uniform structure of the essen- 
tial organs of fructifieation of Composite has, as already men- 
tioned, been adduced as evidence of their comparatively recent 
origin; and this consolidation and uniformity is least marked in 
Helianthoides, most so in Cichoriacem. In many Helianthoides 
we find, for instance, the outer bracts of the involucre more folia- 
ceous, the bracts subtending the flowers (or receptacular palez) 
more normally developed and more firmly attached, the calyx- 
limb (or pappus) less transformed, consisting frequently of per- 
sistent teeth or ariste directly continuous with the ribs of the 
T and thus showing their really calycine nature, the anthers 
in some genera less firmly united and perhaps sometimes quite 
free; and in the female flowers of the Petrobiew we have an or- 
dinary campanulate regular corolla with the anthers (although 
small and sterile) well formed on short filaments alternating with 
the corolla-lobes and far from each other. In Cichoriacew the 
uniformity of the organs of fructification is more absolute than in 
