Arthur W. Hill. 
164 
manner of the two parents, and are thus in striking contrast to 
the usual arrangement of the flowers in the Cowslip X Primrose 
hybrid. The calyx is about 16 mm. in length, slightly inflated, with 
the teeth about 7 mm. in length, triangular to oblong, acute to 
acuminate (Fig. 6). The teeth and sharp ribs are pale-green, 
like those of the Oxlip (Fig. 5), but the membranous portions of the 
calyx between the keeled mid-ribs are not so sharply differentiated 
as in thisspecies. 1 n the Cowslip (Fig. 7), the inflated calyx is uniformly 
coloured of a whitish pale yellow-green hue, varying in length from 
9—15 mm., with teeth 4—5 mm., triangular, ovate, acute. In the 
Oxlip the calyx is from 10—13 mm. long, with teeth about 6 mm., 
narrowly triangular, acute to acuminate. 
The corolla of the hybrid is a clear deep yellow, rather paler 
than the Cowslip, with a deep orange, 5-rayed ring at the throat 
like that of the Oxlip, with the limb saucer to cup-shaped as in the 
Oxlip. The lobes are obovate, subrotund, emarginate, being shorter 
and more rounded than those of the Oxlip. The scent of the 
hybrid approximates closely to the peculiar peach-like odour 
characteristic of the Oxlip. 
The Cowslip x Primrose hybrid or false Oxlip is of interest 
in comparison with our hybrid Cowslip X Oxlip. The leaves shew 
the surface-wrinkling characteristic of the Primrose with the velvety 
tomentum of the Cowslip (Fig. 4). The flower-scape is stout and 
Cowslip-like, but with a more dense tomentum (Figs. 4 and 8), and 
the umbel is composed of more or less erect flowers, shewing the 
Primrose “eye,” and, like that of the Oxlip x Primrose, has a 
somewhat untidy scattered appearance, lacking the graceful drooping 
character of either the Cowslip or the true Oxlip. 
An examination of the flower-scapes of the Oxlip, the Cowslip, 
and of the various Oxlip hybrids by means of transverse sections 
has yielded results of some interest. 
The flower stem or scape of the Oxlip is found to possess a 
narrow band of thick-walled sclerenchyma, which is pericyclic in 
origin and forms a layer of tissue about five cells in depth just 
within the endodermis (Text-fig. 5). In the Cowslip, however, 
where the stem is usually of a greater diameter than in the Oxlip, 
the thickened band of the pericycle is much broader, and is com¬ 
posed of larger cells with thinner walls, which are only slightly 
lignified (Text-fig. 6). The sclerenchymatous tissue in this species 
forms a band some seven cells in thickness, and the greater flexibility 
of the Cowslip stalk is no doubt due to the slight amount of lignifi- 
cation of the walls. 
