A Contribution to Vegetable Teratology. 205 
A CONTRIBUTION TO VEGETABLE TERATOLOGY. 
By A. D. Darbishire, 
Royal College of Science, London . 
[With Text Fig. 27], 
I NHERE is a generally felt suspicion that many of the abnor¬ 
malities which figure as instances of discontinuous variation 
are not of a hlastogenic nature, that they are the result of injury or 
interference, and that they are not inherited. The opportunity of 
testing the latter point in a particular instance has presented itself 
to me. 
The abnormality in question was exhibited by a pod of Piston 
Sativum and was borne on some hybrid plants, of the F 4 generation, 
grown from seeds kindly given to me by Mr. C. C. Hurst. The 
number of pods, in this particular experiment, which passed under 
my eye was 3,833. This alone is 
sufficient to show that the abnor¬ 
mality occurs very seldom. I have, 
at other times, examined a very much 
greater number of pods than this, 
but I have not seen another example 
of this monstrosity. 
The abnormality (see accom¬ 
panying figure) consists in the 
presence of a third valve, which is 
interpolated between the dorsal 
edges of the normal valves of the 
pod, i.e., between the edges oppo¬ 
site to those to which the seeds 
are attached. Looked at from its 
outer surface, this third valve 
appears almost flat at its basal 
end. If we carry the eye slowly 
Text Fig. 27. Abnormal pod of , f , f . 
P>sum sativum. Natural size. to tne nee ena ot ' lie valve ’ we 
