Sinensis gave, under these circumstances, a considerable number of seeds, as the
corolla in falling off drags the anthers, which are seated low down in the tube,
over the stigma, and thus leaves plenty of pollen on it.

HOMOSTYLED SPECIES OF PRIMULA.

It has now been shown that nine of the species in this genus exist under two
forms, which differ not only in structure but in function. Besides these Mr.
Scott enumerates 27 other species which are heterostyled (1/13. H. Muller has
given in 'Nature' December 10, 1874 page 110, a drawing of one of these species,
viz. The alpine P. villosa, and shows that it is fertilised exclusively by
Lepidoptera.); and to these probably others will be hereafter added.
Nevertheless, some species are homostyled; that is, they exist only under a
single form; but much caution is necessary on this head, as several species when
cultivated are apt to become equal-styled. Mr. Scott believes that P. Scotica,
verticillata, a variety of Sibirica, elata, mollis, and longiflora, are truly
homostyled; and to these may be added, according to Axell, P. stricta. (1/14.
Koch was aware that this species was homostyled: see "Treviranus uber Dichogamie
nach Sprengel und Darwin" 'Botanische Zeitung' January 2, 1863 page 4.) Mr.
Scott experimented on P. Scotica, mollis, and verticillata, and found that their
flowers yielded an abundance of seeds when fertilised with their own pollen.
This shows that they are not heterostyled in function. P. Scotica is, however,
only moderately fertile when insects are excluded, but this depends merely on
the coherent pollen not readily falling on the stigma without their aid. Mr.
Scott also found that the capsules of P. verticillata contained rather more seed
when the flowers were fertilised with pollen from a distinct plant than when
with their own pollen; and from this fact he infers that they are sub-
heterostyled in function, though not in structure. But there is no evidence that
two sets of individuals exist, which differ slightly in function and are adapted
for reciprocal fertilisation; and this is the essence of heterostylism. The mere