8o 
Janies Small. 
type, (Fig. 17, M), with a structure very closely resembling that of 
a feather. This occurs notably in Ursinia ; the paleae here make 
very pretty objects under oblique illumination and the structure is 
quite apparent even to the uninitiated. 
As mentioned above, the setae are frequently more or less 
connate at the base, and by the abortion of the free parts we get 
another common form, the fhnbriato-corouiform type (Fig. 17, N). 
In these paleaceous forms the setae are fused laterally with one 
another, but they may also fuse in a clump, when a thick, more or 
less rigid structure arises, which is known as aristate (Fig. 17, O). 
The free ends of the setae are usually blunt and project to a slight 
extent, but each seta may end in a large, strong, acute bristle. This 
type is described as barbato-ciristate , and the bristles may project 
downwards, as in Bidens (Fig. 17, P a ), or upwards, as in Coreopsis 
(Fig. 17, P b ). These aristae are frequently few in number, as one 
would expect when it is remembered that a number of setae go to 
form each one. 
Just as the paleaceous types by extreme reduction give type 
N, these aristate types by fusion and reduction may give a thick, 
cartilaginous ring at the top of the cypsela, which is described as 
corneo-coroniforni (Fig. 17, Q* ). This ring may grow out on one 
side to form an ear-shaped or auriculato-coronifonn pappus, (Fig. 
17, Q b ). The auricle may be simple or lacerate like type K, e.g., 
Pentzia (see 38, Plate X). Finally by a similar reduction we may 
get two horn-like projections (Fig. 17, R). 
Evolution of the Pappus-forms. Most of the evolution of the 
various types of pappus is obvious, but a diagram (Fig. 18) is given 
for convenience. The setose-scabrid type is taken as primitive and 
by fusion at the base with subsequent reduction gives type N. 
This firnbriato-coroniform type, like the simple paleaceous type, I, 
is clearly polyphyletic and may be derived easily from a number of 
types such as b, F, L and K. The evolution of the serrulato- 
paleaceous type, H, is clearly through type C. The various steps 
towards, or the direct evolution of types F, I and M are indicated, 
and the various types arising from the aristate type, O, are 
arranged so that downward lines are lines of reduction and upward 
lines are lines of progressive differentiation. 
The inter-relationships and possible evolutionary connections 
of the various types are somewhat more complex than in Pig. 18, 
but it is considered unnecessary to complicate the matter further 
since alternative methods of evolution of such types as F, GandM, 
