Effects of crossing long-styled and short-styled oxlips with one another and
with the two forms of both parent-species.
Character of the offspring from oxlips artificially self-fertilised and cross-
fertilised in a state of nature.
Primula elatior shown to be a distinct species.
Hybrids between other heterostyled species of Primula.
Supplementary note on spontaneously produced hybrids in the genus Verbascum.

The various species of Primula have produced in a state of nature throughout
Europe an extraordinary number of hybrid forms. For instance, Professor Kerner
has found no less than twenty-five such forms in the Alps. (2/1. "Die
Primulaceen-Bastarten" 'Oesterr. Botanische Zeitschrift' Jahr 1875 Numbers 3, 4
and 5. See also Godron on hybrid Primulas in 'Bull. Soc. Bot. de France' tome 10
1853 page 178. Also in 'Revue des Sciences Nat.' 1875 page 331.) The frequent
occurrence of hybrids in this genus no doubt has been favoured by most of the
species being heterostyled, and consequently requiring cross-fertilisation by
insects; yet in some other genera, species which are not heterostyled and which
in some respects appear not well adapted for hybrid-fertilisation, have likewise
been largely hybridised. In certain districts of England, the common oxlip--a
hybrid between the cowslip (P. veris, vel officinalis) and the primrose (P.
vulgaris, vel acaulis)--is frequently found, and it occurs occasionally almost
everywhere. Owing to the frequency of this intermediate hybrid form, and to the
existence of the Bardfield oxlip (P. elatior), which resembles to a certain
extent the common oxlip, the claim of the three forms to rank as distinct
species has been discussed oftener and at greater length than that of almost any
other plant. Linnaeus considered P. veris, vulgaris and elatior to be varieties
of the same species, as do some distinguished botanists at the present day;
whilst others who have carefully studied these plants do not doubt that they are
distinct species. The following observations prove, I think, that the latter
view is correct; and they further show that the common oxlip is a hybrid between