43 2 Robertson .- — The ‘ Droppers' of Tulip a and Erythronium. 
description of it applies in all essentials to the two other species of which 
I have had material at this stage, namely, T. sylvestris and T. praecox. 
The small bulb is clothed externally by a brown scale leaf. A single 
foliage leaf comes out of the top of the bulb, whilst a whitish stolon — the 
‘ dropper —and a crop of adventitious roots emerge below. If the brown 
scale leaf is removed, a second, and sometimes a third, scale leaf are 
disclosed, differing from the first in being white and succulent, but resem- 
bling it in the ‘ tunicate ’ form (Fig. 2 b). There may be one or more buds 
in the axils of the scale leaves. On removing the scale leaves and buds, 
the only thing left is the dwarf stem, to which are attached the roots, foliage 
leaf, and dropper ; it is found that the latter is actually a continuation of 
the base of the foliage leaf (Fig. 2 c ). It emerges from the bulb by boring 
its way through the scale leaves enclosing it. Sections show that the 
dropper is not a solid structure but a hollow tube, containing in its swollen 
tip a small bulb (Fig. 2 d). Hairs grow from the inner epidermis into the 
cavity of the dropper tube. The length of the dropper may be very great ; 
a bulb of T. sylvestris , dug up in the middle of April, possessed one 
which measured 9§ inches. Later in the year the parent bulb will be 
found to be dead and withered, its stored nourishment and the food 
manufactured by the foliage leaf having passed down the dropper into the 
young bulb at the tip. Eventually the dropper itself shrivels and disappears, 
leaving the new bulb free below. 
The most reasonable view as to the morphological nature of the 
dropper is that it is partly foliar and partly axial, and this conception of it 
is confirmed by the anatomy. As the foliage leaf is tubular at the base, an 
axillary bud would necessarily be completely enclosed by it. The dropper 
is simply formed by the downward elongation of the leaf base fused on the 
adaxial side with the stem rudiment (Fig. 3). The tubular nature of 
the dropper seems to be merely a further step in the tendency to marginal 
fusion which is characteristic of all tulip leaves. This is shown not only 
in the ‘ tunicate ’ scale leaves and the bases of the ordinary foliage leaves, 
but also in the peculiar abnormal leaves, known as ‘ ascidia,’ which are 
occasionally mentioned in the literature 1 . A complication, which has not 
yet been referred to, is the presence of small droppers from the axillary 
buds. These commonly terminate upwards in a rudimentary foliage leaf 
without a blade (Fig. 6 d). They occur chiefly in non-flowering garden 
Tulips, presumably forms of T. Gesneriana. Occasionally droppers of 
very curious form are found. In one specimen of T. praecox^ I met with 
a dropper which, instead of running downwards, doubled sharply on itself. 
1 Germain de Saint-Pierre, Bull, de la Soc. Bot. de France, i, 1854, p. 63. Penzig, Note 
di teratologia vegetale, Malpighia, 16, 1902, p. 168. Miss T. L. Prankerd , B.Sc. has kindly 
shown me a photograph and water-colour sketch of the bulb of a pink-flowering Tulip bearing 
3. short tubular leaf, the upper part of which was pink in colour like the flower. 
