( 386 ) 
But the actual conjugation of the odspore with the male gen- 
erative nucleus was not observed, nor could it be said that 
one of the synergids was not fertilized, though this seems 
improbable. 
The pollen-tube in this family presents some interesting 
peculiarities. In most of the cases studied it proceeds straight 
through the micropyle to the embryo-sac. Butin Cyclanthera 
and Cucumts the pollen-tube becomes dilated in the neck of 
the nucellus which extends through the micropyle and the 
surrounding cells are broken down to make way for it. 
This dilation is carried to an extreme in Cucurbita Pepo, 
which has recently been described by Longo.* In this case 
the tube branches and ramifies in different directions through 
the tissue of the integuments. The writer had hoped to treat 
more fully the subject of fertilization and the behavior of the 
pollen-tube in this paper, but the failure thus far to secure 
the best of material for such a study has rendered it expedi- 
ent to leave this subject for a later contribution. 
In the Cucurbitaceae great interest attaches to the behavior 
of the endosperm. he forms which this tissue assumes 
have already been described. As a rule the divisions of the 
endosperm nucleus occur before the first cleavage of the 
odspore. Fusion of the polar nuclei must take place about 
the time of fertilization; in the cases where it was definitely 
observed it took place slightly before the appearance of the 
pollen-tube, and where the complete fusion was not apparent, 
numerous endosperm nuclei were to be seen while the embryo- 
sac was still undivided. 
The appearance of starch in the embryo-sac at the time of 
fertilization is significant. It is not of general occurrence, 
but was found only in Apodanthera, Bryonopsis, Luffa, Tri- 
chosanthes and Cucurbita. Inasmuch, however, as starch is 
frequently of very transient duration it might have been over- 
looked in others. It is quickly formed as the embryo-sac 
approaches maturity and reaches its maximum before the 
appearance of the pollen-tube. No starch-grains were found 
in any case after the first division of the odspore. In the case 
