360 BOTANICAL GAZETTE [NOVEMBER 
and the whole structure becomes elevated above its original 
position by the elongation of the tissue below the insertion of the 
leaves. In the production of the flower bud, at the summit of 
the aerial shoot, the original stem apex comes to an end. The 
renewal bud for the next bulb is formed as a bud in the axil of 
the inner bulb scale, at the base of the shoot (figs. 25), 26, 27). 
GENERAL SEQUENCE OF FOLIAR OUTGROWTHS FROM THE STEM 
APEX IN ERYTHRONIUM AMERICANUM 
FOLIAR STRUCTURES 
VEGETATIVE BULB 
PERIOD SEQUENCES 
Sequence Character Function Fate 
First leaf Cotyledon Photosyn- | Withers 
First hesis 
Second leaf First scale ropper Husk 
Third leaf Second scale Storage Bulb scale |( Primary 
Fourth leaf First green leaf | Photosyn- | Withers bulb 
Second thesis (husk?) 
Fifth leaf Third scale Storage Outer scale 
Sixth leaf Fourth scale Storage Inner scale | Second 
Seventh leaf Second green | Photosyn- | Withers* ) 
Third ea. thesis 
Eighth leaf Fifth scale Runner Husk Third 
Ninth leaf Sixth scale Storage Bulb scale | bulb 
Tenth leaf Third green Photosyn- | Withers* 
Fourth ‘ thesi 
Eleventh leaf | Seventh scale: | Runner Husk Fourth 
Twelfth leaf Eighth scale Storage Bulb scale |)” pulb 
Thirteenth leaf | Fourth green | Photosyn- | Withers* 
Fifth leaf esis 
Fourteenth leaf | Ninth scale Storage Outer scale | __ 
Fifteenth leaf | Tenth scale Storage € ors 
Sixteenth leaf | Fifth green leaf| Photosyn- | Withers 
thesis 
(and flowjer stalk) t 
* If the bulb is renewed in situ, the base of the leaf becomes the husk of the new bulb; if the new 
bulb develops as a runner bulb, the runner sheath forms the husk. 
t With the development of the floral axis the activity of the primary stem apex ceases, a branch 
apex forming the renewal bulb thereafter. 
This bud is evidently the homologue of bud 2, of the immature 
stages, as indicated in-text fig. 3. The bud is at first distinctly 
in the axil of the scale, but with the upward growth of the adjacent 
shoot it is lifted from its position to one on the base of the shoot 
itself (figs. 27 and 29, 3). 
The apical dome of this bud develops bulb scales during the 
