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SOME PLANT ABNORMALITIES.! 
GEORGE HARRISON SHULL, 
THE investigation of the abnormal, either in the structure or 
function of organisms, is often of great value in arriving at cor- 
rect interpretation of normal conditions. But any specific 
abnormal form is rare as compared with the frequency of the 
normal condition, and as no one observer is likely to discover a 
great number of cases, it is important that all should be 
recorded. 
Already botanists have described very many instances of 
abnormal plant forms, so that the bibliography of plant tera- 
tology is already extensive. Thus Penzig? (1894) gives several 
thousand references to described cases of plant abnormalities. 
I. FASCIATION,. 
This is a common phenomenon, and so widely distributed 
that it has been observed by all who have come into any con- 
siderable contact with plants. The present cases are described 
here because of certain interesting attendant characters which 
may throw some light upon the nature of fasciation. 
A remarkable case of fasciation was observed in Lopéilon 
(Erigeron) Canadense L., where a stem had a breadth, in the dried 
State, of 8.5°™, and the overgrowth at the crest was so great as 
to throw it into marked undulations. The margins of this 
stem were apparently normal, as were also the leaves borne on 
them ; and one margin gave rise to a series of normal axillary 
branches. On the broad sides of the stem, however, the leaves 
were reduced toa narrowly linear form 0.5—2™™ by 2-4. This 
reduction was probably correlated with two other conditions, (1) 
the great crowding of the leaves, and (2) the greatly increased 
surface of the stem compared with its volume. It is certain 
*Contributions from the Biological Laboratory of Antioch College. No. 3. 
* 0. PENZIG, Pflanzen-teratologie. 2 vols, Genoa. 
*901) 343 
