98 DEVELOPMENT OF TULIPA, 



sheaths, the lowest dried, the inmost serving as magazines of 

 nutriment. The bulbs of Tulips differ from those of most species 

 of Allium and the genus Gagea, in that sheaths only spring from 

 the basal axis, and not leaves. It agrees with many species of 

 Allium, as, for instance, A. Scorodoprasum, in that the outer- 

 most sheath is soon dried up, but no such membranaceous sheath 

 is found in the Garden Tulip, as follows the thickened sheaths 

 in the above-mentioned species. 



TCLIPA (tESNERIANA. 



Fritillaria imperialis, L. (Crown Imperial.) 



The well-known thick, somewhat depressed, bulbs of this plant 

 possess, at the time of flowering, strong, generally branched, 

 roots. The broad scales of which the bulb is formed are few iu 

 number, and very fleshy and juicy ; they are more or less con- 

 fluent below, but they are not soldered together into a solid mass. 

 Their free upper margin is, in contradistinction to the lower fleshy 

 part, originally very thin. This, however, soon withers and 

 leaves a scar. In the axis of the uppermost scale in front of the 

 flower-stem, stands the young primary bulb (c). It is formed of 

 from five to seven scales, at present distinct from one another. 

 The first of these on the dorsal side, which is turned towards the 

 peduncle, is tolerably flat, with two angles. 



There is generally in autumn the short dry stump of the last 

 spring's flower-stem in the centre of the bulb ; which is easily 

 drawn out, and frequently carries with it a part of the base of the 

 axis, so that the bulb appears perforated. On the contrary, the 

 scales of the old bulb, which belong to the same axis with the old 

 peduncle, remain in organic connexion with those of the young 

 bulb, which they inclose. Fresh roots spring at this time from 

 the basal axis of this young bulb, perforate the scales of the old 

 bulb and form a circle round their lower half (Fig. 1). The roots 



