Seed in the Scitamineae . 
3i 
part of it (Fig. 62). After fertilization the ovule rapidly 
outstrips the ovary in its growth (Fig. 64), until finally it 
quite fills the cavity, coming into close contact with its walls. 
This intimate relation between seed and pericarp makes 
possible, perhaps causes, the interesting condition here found. 
The ovular integuments remain feebly developed, and the 
function of the testa is assumed by the inner part of the 
pericarp, which develops into a dense, stony endocarp en- 
closing the true seed (end., Figs. 64 , 69). In other words, we 
have here another monocotyledonous stone-fruit, analogous to 
that of the coco-nut, a phenomenon previously unknown in 
the Scitamineae. The following quotation from Richard (’ 31 ) 
seems to indicate that he understood the true morphology of 
the drupe of Heliconia , but I find no reference to it by later 
writers : ‘Nucularum testa tenuiuscula et sub-osseocartilaginea 
includit semen unicum cavitati compar ; integumento proprio 
tenuissimo vix secernendo etiamque non nisi furfuratim sepa- 
rabili.’ 
Let us examine the fate of the tissues in detail. The 
inner integument becomes finally reduced to a mere line in 
a section of the ripe seed (i. i., Fig. 70). The outer integu- 
ment retains its primitive condition practically unchanged. 
Originally about seven cell-layers in thickness with the outer 
layer forming a sort of epidermis ( o . i ., Fig. 65), this is found 
to be its structure in the ripe seed ( 0 . i., Fig. 70). No trace 
of any special arillar or chalazal development is found, nor 
any infolding to form a micropylar collar. Many cells of 
the endocarp early show an elongated form, and these are 
irregularly intermixed with groups and rows of parenchy- 
matous cells (end., Fig. 65). The inner layer bordering the 
seed forms an epidermis. As differentiation proceeds, all 
the cells except those of the epidermis thicken their walls, 
but in varying degrees, so that the final result is a rather 
irregular mixture of sclerenchyma-fibres and sclerotic cells, 
forming a layer almost as dense and hard as the endocarp of 
a cherry (end., Fig. 70). At the outer margin of the endocarp 
the cells remain thin-walled, and become at length empty. 
