152 BOTANICAL GAZETTE [AUGUST 
spirems, the steps being very similar to those of the first division, 
and it is concluded that in all probability they come from the 
maternal and paternal source respectively, in spite of the fact that 
in the formation of the daughter nucleus the chromatin has appeared 
completely fused. Since the subsequent divisions were not fol- 
lowed, it could not be determined how long this dual nature per- 
sisted. 
The account of fertilization in Abies balsamea by HUTCHINSON 
(12) varies somewhat from that of FErGuson. The contents of the 
male nucleus pass into the nucleus of the egg, although the chroma- 
tin groups remain distinct, and later, when the two sets of spindle 
fibers are formed, two sets of chromosomes arise from the respective 
nuclei. These two spindle complexes unite and the chromosomes 
of the maternal parent pair with the chromosomes of the paternal 
parent, after which the fibers disappear. The members of each pair 
twist about each other, bend, and become transversely segmented 
at the bend so that there are 2x pairs in the fertilized egg. When 
the second set of fibers appears, the members of the pairs resulting 
from the transverse segmentation separate for the opposite poles. 
HEATLEY (11) has described the development of the embryo 
sac of Trillium cernuum, in which the sac arises from the chalazal 
daughter nucleus of the megaspore mother cell, two megaspores only 
being functional. Each functioning megaspore divides twice to 
form the typically arranged 8-nucleate embryo sac. 
In the present study it was not considered necessary to work 
out the development of the sac, and furthermore, no attempt has 
been made to determine the method of entrance of the sperms into 
the sac or their passage to the egg and polar nuclei. BLACKMAN 
‘and WELsForRD (1), Ernst (3), GUIGNARD (6, 9, 10), MOTTIER 
(13, 14), SAX (16), and STRASBURGER (17, 18) have reported on the 
earlier phase of fertilization, and on the whole have agreed. These 
same authors have also described in detail the coming together of 
the nuclei, their chromatin condition, and the breaking down of the 
nuclear membranes separating them, although GuIGNARD (7-9) 
differs somewhat from the others on the latter point, which will be 
spoken of later. By comparing these investigations with those of 
Pinus (FERGUSON 4, 5) and Abies (HUTCHINSON 12), it is apparent 
