THE COMMON AVENS, OR HERB BENNET— continued. 
stage ; whilst the spreading, bright yellow, obovate petals are about as long as the 
sepals. The crowded stamens and the stigmas reach maturity at about the same 
time, or the latter a little in advance ; and, as in the case of the Tormentil, the 
flowers are stated to secrete more honey in the North than with us. Some flowers 
are occasionally entirely staminate. 
The flowers are succeeded by a conspicuous chestnut-brown bur, the develop- 
ment of which is extremely curious. The numerous carpels are borne on a flat, or 
only slightly projecting, hairy receptacle, and their ovaries are also thickly covered 
with hairs. The terminal styles are at first straight ; but later a projection springs 
from each a little below its apex and elongates in an upward curve, ending in the 
stigmatic surface. The apex of the original style then bends over the base of this 
projecting portion. In this species the upper joint has a few minute hairs at its base 
and reaches a length of about half an inch, which is considerably less than that of 
the main body of the style. After fertilisation the base of the style becomes dry 
and rigid, while the upper joint shrivels and becomes detached at its base, leaving 
the extremity of the original style as a strong, sharp hook. The one-seeded achenes 
are so arranged on the receptacle that these hooked awns, as they are sometimes 
termed, spread outwards almost in a sphere, whilst the attachment of the ripe carpel 
at its base is but loose. This arrangement thus forms a most effective bur, the 
hooks catching in the fur of any passing animal of a height of one or two feet from 
the ground, as they do in the clothes of any human being, and the carpels being thus 
carried either singly or collectively to a distance. 
Such elaborate adaptations for the dispersal of seed — whether by wind, for which 
purpose we find various forms of wings and parachute-like plumes of hair, or, as 
here, by animals, for which there are countless varieties of bur and of attractive 
succulence — are, perhaps, more variable within the limits of single genera than are 
the equally elaborate contrivances for pollination by wind or by insects. To the 
evolutionist this would suggest that they are of more recent geological date. 
