TULIP DROPPERS 471 
Not one of the bulbs of these special plantings developed a 
dropper. 
In other plantings of tulips, of the smaller bulbs planted in 
autumn at a depth of two inches there has been an occasional 
dropper but usually its length was short. It is clear that 
vegetative bulbs planted at shallow depths in autumn do not 
regularly develop droppers at least in the first year of their 
growth. The ability to form droppers, which it seems is 
characteristic of seedling tulips, appears to be lost in the small 
bulbs of cultivated races propagated by vegetative multipli- 
cation. 
At the New York Botanical Garden the best cases of droppers 
in the tulip have been found in beds whose bulbs have remained 
undisturbed for several years and in which the proportion of 
flowering plants was greatly decreased. They have been found 
in beds planted with bulbs of small size, but by far the greater 
number of such bulbs did not produce droppers. 
The formation of droppers is also known for species of Gagea, 
a genus of bulbous plants indigenous to the old world, and for 
Erythronium of which the yellow adder’s tongue is a well known 
species of the eastern United States. 
The droppers of the Erythroniums have been described and 
figured in American botanical journals. They differ from 
the droppers of the tulip in that the vegetative leaf does not 
contribute to the structure. The dropper is formed from the 
Part of the stem and from the scale next inside the vegetative 
leaf. Droppers also develop from lateral buds and the stem 
and leaf portions of these are more or less fused with the main 
dropper which thus appears to be branched. 
The number of species whose seedlings or vegetative bulbs 
have the ability to burrow to lower levels by the formation of 
droppers is few. Most bulbous plants burrow to lower depths 
by means of contractile roots. The dropper is a highly special- 
ized structure produced by the extremely asymmetrical but 
coérdinated growth of a node and the two internodes adjacent 
to it. 
