1918] OTTLEY—IMPATIENS 299 
cells near the base of the micropyle and the contents of these 
cells stain diffusely. This appearance also extends out laterally 
and at this time up to the tip of the inner integument (fig. 9). 
The cells are crowded and their cytoplasm and nucleoplasm stain 
so diffusely that no attempt was made to represent their appearance 
in a sketch. As will be seen later, these cells break down during 
endosperm formation, and this doubtless represents an early stage 
in their disintegration. This characteristic progresses chalazally 
in the tapetal cells as the embryo sac develops and reaches the basal 
cells during early endosperm formation. 
In an 8-nucleate stage the lower half of the tapetum is still 
normal and contains a decidedly granular cytoplasm and _nucle- 
oplasm which suggests the presence of food particles. This granu- 
lar appearance is not visible in the cytoplasm of the other cells 
of the inner integument, although they stain more densely than 
do those of the outer integument. GuIGNARD (22) says that a 
nitrogenous substance accumulates in the tapetal cells of J. par- 
viflora and that in all of the Balsaminaceae there is this proteid 
layer of tabular cells. 
BILLINGS (7) believes with most students that the tapetal 
layer, whether from the inner integument or the nucellus, serves 
a nutritive function, dissolving and absorbing nutriment from the 
surrounding integument, and that its function is not simply pro- 
tective, as given by HEGELMAIER (27). VANDENDRIES (44) in a 
study of the Cruciferae finds the tapetum a part of the inner integu- 
ment, but believes it plays only a protective function. One reason 
given is that in the antipodal region, where the tapetum is separated 
from the sac by a small mass of nucellar cells, it presents the char- 
acteristic appearance of young and active tissue. This reasoning 
oes not seem conclusive to me, since it may well be that this was 
a region of considerable food and that here the active cells of the ta- 
petum digested and absorbed it and then passed it up to the embryo 
sac. In J. Sultani the tapetum persists longer at the antipodal end 
and it is here that growth takes place until the sac reaches the 
chalaza and passes slightly beyond the end of the tapetum. 
- _Bauicka-Iwanowska (5) studied certain “Gamopetales” and 
described the tapetum. In agreement with CHopat (13) and most 
recent writers, he does not believe that the tapetum is for protection, 
