On the Species of the Genus Primula in Essex. 209 
together, but never where only one grows. 66 Darwin suggests 
that its frequency in some places may be due to a particular 
species of moth or other insect which visits both plants, but, 
until we know more certainly what insects visit either species, 
this point must remain unsettled. The period at which these 
Hybrid Oxlips flower is probably very largely regulated by 
the parent the hybrid most takes after, but I was surprised 
to see one partaking strongly of the Cowslip nature out as 
early as March 7th last. They not unfrequently remain in 
flower until quite the end of May, when all other Primulas 
are over. This I suppose to be due to their want of fertili¬ 
zation, as many flowers remain out for a long period when 
fertilization is prevented; but these hybrids, as usual, are to 
a large extent sterile, and therefore cannot be fertilized. 
The Hybrid Oxlip is, on account of the absence of the 
Primrose, but very little mixed with P. elatior in the district 
inhabited by the latter, except just on the extreme edge of its 
area. It is rather strange that in several woods in the 
neighbourhood of Saffron Walden all the forms (Cowslip, 
Oxlip, Primrose, Hybrid -elatior, and Hybrid Oxlip) should 
grow. This, the late Mr. Gibson informed me, is the case in 
Quendon Wood. I have already spoken of Westley Wood 
and Grim’s Ditch Wood, on opposite sides of the Slade 
Valley. In the former I have for three years running found 
all the forms, and this year (1883) also in the latter. Prim¬ 
roses abound in Westley Wood, and in several places 
Cowslips extend a little way up the paths, and as a con¬ 
sequence there are a few plants of the Hybrid Oxlip, while 
on the edge nearest to Grim’s Ditch Wood are a few plants of 
56 The Hybrid Oxlip is said, on good authority, never to be found on 
the Continent, where the Primrose and the Cowslip do not grow inter¬ 
mixed as with us. Nevertheless there is at Kew a specimen labelled 
“ P. officinali-vulgaris, Pres Montreux, Yaud, 15-4-75, F.,” which seems 
to be identical with the Essex plant of the same name. Many other 
specimens which appear to me to be hybrids with elatior are arranged 
with English Hybrid Oxlips (P. veri-vulgaris) under the name of “ P. 
variabilis , Goup.” One such is labelled “ Hotel Byron, nr. Chillon, 
Avril, ’51. Cette plante hybride de la P. acaulis et de la P. officinalis 
n’est pas rare dans les environs de Montreux, G. M.” 
