72 
James Small. 
many genera. The phylogenetic results obtained by Lavialie have 
been mentioned already (Chap. I, Sect. A, and Fig. 3). In addition 
he gives a very complete summary of our knowledge of the fruit 
in the Compositae, dealing with the ovule, epithelium of the 
embryo sac, the haustorial function of the antipodal cells and 
other matters, which may have a certain phyletic value but 
which are outside the scope of the present chapter. 
Joxe (42) gives details of the various types of germination in 
the Compositae, some of which are quite aberrant. Hanstein (27), 
Haberlandt (22) and Yapp (71) mention the capitate hairs which 
are so characteristic of certain genera, notably Helianthus, 
Calendula and Inula. 
Achenial Hairs .—The most interesting part of the pericarp 
from the present point of view is, however, the hairs which occur 
on very many of the fruits. These were studied in detail by 
Macloskie (49), and, as they appear to be of considerable phyletic 
value, they will now be considered in some detail. The curious 
duplex hairs of the cypsela of Senecio vulgaris have long been 
objects of interest. They are situated in the furrows between the 
ridges of the pericarp, and are composed of two cells placed side 
by side, each containing a spiral fibre, which on being moistened 
swells and shoots out at the top of the cell, showing movements like 
those of the elaters of the liverworts. This double tube is mounted 
on a pedestal of two clear cells (Fig. 11). 
Archer (1) and Kraus (44) mention these duplex hairs as 
common in the Compositae. Macloskie examined genera from 
most of the tribes, and says “ the consideration of the facts stated 
above suggests a somewhat different line of affinities from that 
usually adopted.” He did not, however, make any definite phyletic 
suggestion. Harz (28), Heineck (29), Nichols (53) and Lavialie (45) 
extended the observations, but again drew no definite phyletic con¬ 
clusions, so that we are free to make what use we can of the facts. 
The duplex hairs with elaters are characteristic of the 
Senecioneae, similar duplex hairs with acute tips and no elaters, 
occur in the Astereae, Eupatorieae, Vernonieae, Heliantheae, 
Helenieae and Arctotideae. The Anthemideae have no such hairs 
but cells with spiral filaments occur on the outside of the pericarp 
in certain cases (Figs. 12-13). 
The Calenduleae are probably similar to the Senecioneae 
according to Macloskie, with the addition of the above-mentioned 
capitate hairs. The cypsela of the Cichorieae is glabrous but 
