22 
THE PLANT WORLD. 
leges in order to see whether attention is paid only to'practice, 
or whether theory also occupies its necessary place in instruction. 
Fannie Kagan. 
An Anomalous Structure on the Leaf of a Bean Seedling.* 
Some red Valentine beans were ger¬ 
minated in soil under a bell jar with 
high temperature and relatively high 
humidity. After a week’s germination, 
one seedling showed two unusual out¬ 
growths ; one just below the cotyledons, 
the other upon the lower surface of one 
of the plumules, closely appressed to the 
midrib. Both structures appeared to be 
strong root tips, were without chloro¬ 
phyll and bent away from the light. The 
lower structure possessed a blunter tip 
than the upper, and had bent downward. 
No further development showing, it was 
sectioned for microscopic examination, 
and the structure characteristic of a true 
root were found. A week later the entire plant was becoming un¬ 
healthy. The abnormal plumule was examined microscopically. 
Fig. 7. Longitudinal section of structure shown at b, Fig. 6. (After 
Horne.) 
Cross-sections at different intervals from its base showed the out¬ 
growth starting as an enlargement of the parenchyma surround- 
* Horne, W. T., Bull. T. B. C. 31: 585. Nov. 1904. 
Fig. 6. Bean Seed¬ 
ling with anomalous 
structures at a and b. 
(After Horne.) 
