ENDOSPERM OF UTRICULARIA 9 
The tubes strike the stylar canal at various heights above the 
ovary, and all seem ultimately to reach it, though some enter 
it very close to the base (Fig. 1). 
The pollen tubes enter the ovary as a rope which quickly 
separates into its individual strands as the pollen tubes scatter 
among the ovules. The tubes are large and conspicuous, stain 
brilliantly, and so show conspicuously in sections. They creep 
along the placental surface where some of them encounter the 
protruding lobes of the female gametophyte (F%g. 9). This pre- 
sents a type of conjugation unusual in Angiosperms; two 
naked protoplasmic masses come together outside the ovule when 
the pollen tube meets a lobe of the female gametophyte in the 
free space of the ovary. 
The membrane investing the pollen tube seems to hold for 
some time after entering the female gametophyte, and all the 
evidence indicates that the tip of the tube follows its customary 
route to one of the synergids. In this instance the synergid is 
submerged within the cytoplasm of the embryo-sae and lies well 
towards the dorsal side, so that the pollen tube has to take a 
rather indirect course to reach it. The proof here is unusually 
strong that the synergid exercises a chemo-directive influence 
on the pollen tube, which in this instance could more easily 
have reached the egg directly. The gorged synergids stain 
brilliantly with safranin for some time, but the reaction grows 
fainter until by the time the embryo is well started the dilated 
synergid with the same stain appears as a grayish mass near 
the base of the suspensor. In Polypompholyx where similar 
conditions occur Lang (6) could not trace the pollen tube to 
the synergids. 
The micropylar end of the embryo-sae often contains a large 
amount of material that seems to have come from supernumer- 
ary pollen tubes that possibly may have later discharged their 
contents into the embryo-sae (Figs. 8, 9). One of the writers 
(8) had previously noted in Elodea that the first and second 
tubes to enter the ovule terminated in the two synergids, and 
that if an additional tube entered, this discharged directly into 
the embryo-sac. In some eases all nuclei of the female game- 
tophyte were obscured by this strongly staining mass that 
seemed to have come from the pollen tubes. This behavior is 
