Seed in the Scitamineae . 
29 
Strelitzia Reginae , Ait., shows some points of interest in the 
structure of its seeds, which appear not to have been studied 
since the time of Gaertner (1791). The ovule (Fig. 51) is not 
peculiar. The inner integument becomes reduced to a thin 
layer with the exception of its thickened micropylar end, 
which is recognizable until the seed reaches its adult size 
(/. i., Fig. 53). The outer integument attains a considerable 
thickness and consists of many cell-layers (Fig. 54). Of these 
the cells of the inner layer are finally cuboidal and thin-walled 
(int., Fig. 56). Those of the outer layer take a similar form, 
but remain smaller and thicken their walls until but a very 
small lumen remains [ext., Fig. 56). All the intermediate 
tissue constitutes a nutrient layer which becomes reduced in 
the ripe seed to a thin, dense mass {nut., Fig. 56), the com- 
pression first showing itself next to the outer layer (nut., Fig. 
54). The chalazal end shows no special differentiation, and 
no trace of the micropylar collar, so usual in this group, is 
found. At the micropylar end there appear, even before 
fertilization, papillar outgrowths from the free end of the outer 
integument and from the part of the funiculus lying opposite 
(ar., Fig. 52). These elongate into the multicellular fibres 
which in the ripe seed form two dense woolly tufts, of a deep 
orange colour, at the micropylar end [ar., Fig. 55). The 
structure of these arillar fibres has lately been described by 
Pfeiffer (’ 91 ). They arise from the sides of a caruncle-like 
outgrowth formed by the coalescence of the ovular regions 
from which the outgrowths spring. The body of this caruncle 
consists of undifferentiated tissue which is directly continuous 
with the nutrient layer of the testa, but which, unlike the 
latter, preserves its cellular structure. Up to the point where 
the arillar threads begin, the surface is protected by an outer 
layer, like that of the testa. This aril is evidently quite 
homologous with those of other Scitamineae, the differences 
being merely in detail. I can add nothing to the speculations 
of Pfeiffer (’ 91 ) and others concerning the use of these brilliant 
woolly tufts. 
The embryo-sac increases in size during the development 
