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Mutations and Evolution. 
From a study of the early records, Miyoshi concludes that a 
large number of cultivated sorts existed two centuries ago, and 
has been largely added to during the last hundred years. The 
many forms which receive botanical names for the first time are 
distinguished by such features as leaf colour, flower colour, singles 
or doubles, fragrance, inflorescence, and pubescence. The 
multiformity of the group is comparable with that of the North 
American Crataegus, or with Draba verna or Viola tricolor , and 
the forms appear to have arisen as mutations. Seeds in most 
cases yielded a uniform offspring, but it seems possible that some 
mutational characters may have been transferred by crossing. 
Peloria. 
Peloria, or the sudden development of actinomorphic flowers 
in a zygomorphic species, has been studied most extensively in the 
Scrophulariaceae where it occurs most commonly, although it is 
also found in the Labiatae, Leguminosae, Orchidaceae and other 
families with zygomorphic flowers. It is of evolutionary interest 
because zygomorphy is supposed to have been gradually developed 
in relation to the visits of insects, while peloria is a sudden 
re-expression of symmetry. 
Peloria behaves in part as a recessive character, is known to 
occur as a variation in numerous wild species, and in a few cases 
has become a specific character, indicating that in such cases 
zygomorphy is not essential for survival. De Vries 1 studied 
peloria in Linaria vulgaris for thirteen years and gives the 
literature of the subject up to the time of his work. He mentions 
Mentha aquatica as a species whose apical flowers are always 
peloric, and Uropedium Lindenii , found in Colombia, as the peloric 
form of Cypripedium caudatum . It is not impossible that the 
Ranunculaceous genus Aquilegia, with its five spurs, arose as a 
peloric mutation from a zygomorphic one-spurred ancestor. The 
increased number of nectaries should give it an advantage as 
regards insect visits. 
The genetical studies of peloria appear to have been confined 
to the Scrophulariaceae, but in this family the genera Linaria, 
Antirrhinum and Digitalis have given valuable results. The earliest 
discovery of a peloric condition in Linaria vulgaris was made by 
Zioberg in 1742. On an island near Upsala he found among the 
normal a plant bearing only regular flowers, and Linnaeus described 
it under the name Peloria . There are numerous later records of 
1 The Mutation Theory, Vol. II. 
