other species of the genus. For instance I raised a red primrose from seed from
a protected plant, and the flowers, though still resembling those of the
primrose, were borne during one season in umbels on a long foot-stalk like that
of a cowslip.

With regard to the second class of facts in support of the cowslip and primrose
being ranked as mere varieties, namely, the well-ascertained existence in a
state of nature of numerous linking forms (2/12. See an excellent article on
this subject by Mr. H.C. Watson in the 'Phytologist' volume 3 page 43.):--If it
can be shown that the common wild oxlip, which is intermediate in character
between the cowslip and primrose, resembles in sterility and other essential
respects a hybrid plant, and if it can further be shown that the oxlip, though
in a high degree sterile, can be fertilised by either parent-species, thus
giving rise to still finer gradational links, then the presence of such linking
forms in a state of nature ceases to be an argument of any weight in favour of
the cowslip and primrose being varieties, and becomes, in fact, an argument on
the other side. The hybrid origin of a plant in a state of nature can be
recognised by four tests: first, by its occurrence only where both presumed
parent-species exist or have recently existed; and this holds good, as far as I
can discover, with the oxlip; but the P. elatior of Jacq., which, as we shall
presently see, constitutes a distinct species, must not be confounded with the
common oxlip. Secondly, by the supposed hybrid plant being nearly intermediate
in character between the two parent-species, and especially by its resembling
hybrids artificially made between the same two species. Now the oxlip is
intermediate in character, and resembles in every respect, except in the colour
of the corolla, hybrids artificially produced between the primrose and the
polyanthus, which latter is a variety of the cowslip. Thirdly, by the supposed
hybrids being more or less sterile when crossed inter se: but to try this fairly
two distinct plants of the same parentage, and not two flowers on the same
plant, should be crossed; for many pure species are more or less sterile with