581 
On the Inheritance of Heterostylism im Primula. 
By W. Bateson, M.A., F.R.S., and R. P. GRecory, M.A. 
(Received July 31, 1905.) 
In view of the results obtained by Darwin,* Hildebrand and others, it 
seemed likely that the characters long-style and short-style, well known in 
Primulacese and other orders, might have a Mendelian inheritance. Our 
experiments have shown that this is the case in P. sinensis, the short style 
being dominant, the long recessive. 
The inheritance is usually of the simplest type. In one case (p. 584) there 
was considerable divergence from the expected proportions, and it is no doubt 
possible that this case was one of real abnormality; but we incline to think 
that the irregularity was due to accident or error. But besides the cases 
which can be regarded as normal one individual short-styled plant gave an 
entirely aberrant result (p. 584); and as the offspring of this plant gave results 
similarly aberrant, there can be little question that we are here concerned 
with an inheritance of a special type. Further experiments with this family 
are in progress. 
Another feature of interest was seen in the F2 families raised from matings. 
in which an equal-styled race was used, the phenomena well illustrating the 
mode of appearance of a new type by the recombination of the factors. 
brought in by the pure parental types. 
Horticultural experience as to the production of long- and short-styled 
offspring is in general harmony with our results. Fashion has decreed that. 
P. sinensis shall be exhibited in the long-styled form alone. This being the 
recessive, breeds true, and short-styled plants are consequently absent from 
selected strains, being even difficult to procure at the present time. The 
florists’ Auricula, on the contrary, must be exhibited in the short-styled or 
“thrum” form, but as this is the dominant, long-styled Auriculas continue 
abundant. 
In the wild Primrose (P. acaulis, Jacq.) the two forms are about equally 
numerous in nature. Experiments with this species, now in progress, give 
indications that the inheritance of the two types follows the same rules. 
From the greater sterility of its illegitimate unions the Primrose is less easy 
to work with, and as might be expected from the same cause, all short-styled 
* “Forms of Flowers,’ edit. 1884, giving references to the principal memoirs on the 
subject. 
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