42 Gibbs. — Notes on the Development and Structure of 
certainly do not form a proteid reserve, and they are too active in 
appearance not to suggest some necessary function. The proliferation 
occurs on the first divisions of the suspensor. On maturity the whole 
wing dries up forming merely a means for the dispersal of the seed. The 
differentiation of this wing at such an early stage would support the idea of 
transitory water storage, the later function to facilitate dispersal being only 
a secondary result of the transitory nature of the first. 
If we take this view in the case of Spergula arvensis , there seems no 
reason not to apply it to the morphological representative of this tissue in 
Stellaria media where it is reduced to one layer which would thus form 
a specialized water jacket and not a transitory proteid reserve. This would 
bring the whole question into line with Balfour’s apposite suggestion and 
seems to be the view borne out from the ontogenetic standpoint. 
Chalaza. The chalaza is composed of small polygonal cells with 
large nuclei and dense homogeneous contents. These cells are in direct 
continuity with the nucellar axile cells and also with the layers of the 
integuments (PL V, Fig. 12, chat). The vessels of the funicle abut on this 
tissue, branching as the ovule increases in size (PI. V, Figs. 12, 18, 19, v.bi). 
In early stages it gives a xanthoproteic reaction. Before the funicle breaks 
off the cells become impregnated with tannin, and after rupture takes place 
it is bent up against the micropyle forming the hilum (PL VI, Figs. 22 and 
24, h). 
Germination of the Seed. 
Cerastimn perfoliatum . 
Germination begins by the elongation of the cotyledons into the 
central mass of perisperm, thus forming the first twist of a spiral (PI. VI, 
Fig. 24). This elongation was observed in one or two cases in the mature 
seed, but is exceptional before actual germination, or hydrolysis of the 
starch reserves takes place. 
In this stage the axile cells of the nucellus are elongated, and press 
laterally on the region between the hypocotyl and the cotyledons (PI. VI, 
Fig. 24, ax. c .). They show a marked decrease in starch contents in the 
vicinity of the endosperm cap, the cells of which, on the axile side, 
practically form part of the nucellar tissue. The chalazal cells are almost 
obliterated, but the cuticularized layers of the ‘ aerenchyma ’ are apparent, 
large air spaces occurring in the nucellar cells immediately above them 
(PL VI, Fig. 24, a. s.). Transverse sections best show the intimate relation 
of the endosperm cap to the nucellus and root apex of the embryo. The 
activity of the endosperm is greatest in the first stage of germination, 
starch appearing in the epidermal cells of the embryo as soon as the growth 
of the cotyledons begins. A transverse section through the root cap shows 
the procambial strand (Fig. 25, pc. s.), the cortex, the outer layer of which 
