ENDOSPERM OF UTRICULARIA ii 
into the antipodal end of the sac, and the tissue bordering this 
region soon disintegrates, so that presently two large endo- 
sperm cells come to lie side by side in a caecum protruding 
beyond the original limits of the embryo-sae (Fig. 12). Mean- 
while the antipodal nuclei have disappeared entirely as the ag- 
gressive endosperm shoved past their original location. 
The antipodal haustorium rapidly digests its way through all 
intervening cells and mushrooms out against the epidermis of 
the ovule (Fig. 11). The cells of this limited layer seem to be 
weakened under the attack, and the epidermis covering the 
haustorium becomes thinner than elsewhere. The epidermal 
cells of this region shrivel in preservatives and the riper seeds 
commonly show an opening through the outer investment at this 
point (Fig. 10). 
The antipodal haustorium persists until the embryo is far 
advanced. It gradually flattens as the seed matures, and at a 
late stage shows only as a collapsed cap at the end of the embryo. 
Its nuclei become enormously enlarged, measuring 19x12 micra. 
Neither of its nuclei seems ever to divide. 
It seems likely that the massive epidermis of these ovules 
functions both mechanically and to conduct materials. Its large 
cells show much starch, suggesting nutritive significance. The 
behavior of the antipodal haustorium might be explained as an 
attack on foods stored in the epidermis or being conducted 
through the cells of this layer. 
MICROPYLAR HAUSTORIUM 
The micropylar haustorium as noted above begins much earlier 
than the antipodal outgrowth, which is a post-fertilization de- 
velopment. The encroachment upon the tissue of the placenta 
noted above is launched by the protoplasm of the female game- 
tophyte. Previous to fertilization it may have penetrated to a 
depth of two layers of cells, though no nuclei are thrown into 
the lobe at this stage (Fig. 8). 
Early in the development of the endosperm two of its nuclei 
slide past the embryo and distended synergids, and enter this 
pouch (Fig. 12). Their arrival starts the second phase in the 
development of this haustorium, which then penetrates farther 
