Mutations and Evolution , 
183 
and hence fall in class (3). Bateson (1902) first pointed out that 
in reciprocal crosses made by Darwin between normal and peloric 
snapdragons, the peloric character behaved as a simple Mendelian 
recessive, giving 90 non-peloric to 37 peloric in F 2 . Darwin, 
however, speaks of two of the 90 plants as being “ in an intermediate 
condition between the peloric and normal state.” The exact 
nature of these intermediate plants is not clear. If they 
correspond to Baur’s class (2), then the actual numbers 88 : 2 : 37 
should be compared with an expectation of 72 : 24 : 32 for the ratio 
9:3:4. Hence if the behaviour was the same as Baur describes 
there would be a large excess of normals to account for, and a 
corresponding defect of “ intermediates.” 
It is thus obvious that peloria, like doubling, though originating 
through mutations, behaves differently in different genera. 
Other mutations in wild and cultivated plants. 
These records are sufficient to show the frequent occurrence 
of doubles in wild species as parallel mutations, and also of peloria, 
especially in the Scrophulariacese. That they are obviously not in 
any phylogenetic line of descent however, and are more or less 
incapable of reproducing themselves, detracts somewhat from their 
evolutionary interest. We may therefore consider some other types 
of polymorphism which have arisen in wild species or in cultivation. 
It has been found practically impossible to draw a line between 
mutations occurring in controlled cultures and the obviously 
similar changes which are frequently found wild. We therefore 
feel justified in extending the mutation conception to these wild 
forms and varieties. 
Linaria alpina, a species of the Alps and Pyrenees, has two 
varieties, rosea and concolor, whose genetic relationships have been 
investigated by Miss Saunders (1912). In the typical alpina, which 
is most common in the Alps, the corolla is blue, with an orange 
palate, which is partly due to the presence of a viscous orange-yellow 
fluid in the epidermal cells and the hairs of the beard and partly 
to the yellowish colour of the cuticle. The var. rosea, which is 
rare and confined to certain stations, is pink with orange palate 
and behaves as a simple recessive to the type. Var. concolor is 
blue without the orange palate, and this is dominant to the type. 
Each of the varieties therefore differs from the type by one factor, 
but it is uncertain which was the original form. In L. vulgaris, 
which is yellow with orange palate, de Vries 1 found on crossing with 
1 Mutationstheorie, II, p. 152, 
