34 Achenial Hairs and Fibers of Composite. [January, 
other tribes of Composite. It is not improbable that we may find 
rudiments of the hooked hairs even in such of the species as are 
described as having glabrous achenes. Descriptive botanists may 
fairly characterize parts as “smooth” when hairs, if present, are 
not prominent; but in seeking to find the affinities of tribes and 
genera, we must do our utmost to detect hidden marks, and thus 
the structure of these hairs has a higher significancy than the de- 
gree of their development. : 
Duplex hairs are general in Asteroideæ, Eupatorieæ, Ver- : 
noniez, Helianthoidex, Helenioidee, Arctotidez, and Mutisiez, 
but we have found no trace of them in Anthemidez or in Cicha- 
riee, The Cynaroidez appear to me to present two types of - 
structure ; some genera (as Carlina and Xeranthemum) agree a 
A evides; whilst the true thistles agree with Cichorieæ. Cen- 
taurea (C. nigra, C. scabiosa, C. terniflora) has the achene covered 
in some cases (as Callistephus chinensis, the China-aster) man 
jointed hairs like those of the perianth are intermingled with d 
plex hairs on the fruit. Engelmannia (of Helianthoidez) is said 
is true of the aberrant Ambrosia. 7% agetes erecta (the large 
can marigold, of Melenioidez) has the achenial hairs short 
lanceolate, but its congener, 7. patula, shows that this is a mer 
variation of the duplex type. In some cases where we sho 
expect to find duplex hairs, a cursory examination will sugg 
that they are simple; but here a closer view is apt to show 
rudiment of the missing half, like a small twin brother, at base ® 
the larger part (as Liatris scariosa, Fig. 6, D.). It is always th 
basal division of the cell which is less fully developed. Th 
_ tition between the chambers of the duplex hair is usually p 
and sometimes we could chase air-bubbles up and down 
tubes. 
The genera of Anthemidex have, nearly all of them, glabr 
Leucanthemum. (Fig. 8.) Achillea mille cfolium seems 
have these, but its pericarp has internal glands within its cel 
