1918] WENIGER—FERTILIZATION 261 
each splits longitudinally. In 1895 Morttrer (13) first described 
the vermiform shape of the male nuclei in Lilium Martagon. 
~The male and egg nuclei fuse in the resting condition after com- 
ing in contact and are figured as forming a resting nucleus. In 
1898 NAWASCHIN (15) announced the discovery of double fertili- 
zation in Lilium Martagon and Fritillaria tenella. The male 
nucleus that fuses with the polar nuclei loses its spiral form, but 
the 3 nuclei remain distinct until the prophase of the division. The 
fusion of the 3 nuclei occurs when the numerous chromosomes come 
together on the equatorial plate. ‘‘ Fusion occurs, not in the resting 
stage, as Morrier indicates, but in the prophases of the division, 
as GUIGNARD first observed.”’ 
The motility of the male nuclei is described for Lilium Martagon 
and Fritillaria tenella by NAWASCHIN (16, 17); for the tulip by 
GUIGNARD (11); and for Lilium Martagon and L. auratum by 
BLACKMAN and WELSFoRD (2), and Miss WELSFORD (23). These 
authors attribute independent motion to the male nuclei. 
In Paris quadrifolia and Trillium grandiflorum Ernst (6) finds 
a striking difference between the fusion of the male nucleus with the 
egg and that with the polar nuclei. In the former case the fusion 
is complete, so that a typical resting nucleus is formed. In the 
latter case the polar nuclei begin to form spiremes even before the 
male nucleus arrives, and in the group of the 3 nuclei (the 2 polar 
nuclei and the male nucleus) 3 spiremes are distinguishable. 
Distinct maternal and paternal chromosomes were first described 
for an angiosperm by Miss Pace (21). She found spiremes in all 
nuclei of the embryo sac of Cypripedium before fusion took place. 
The spireme was well formed in every nucleus, and shortened almost 
enough to segment into chromosomes. ‘It would ‘seem in this 
case, that if fusion does take place, there could be no possibility 
of a fusion of the chromatin, which would certainly divide into 
chromosomes from the spireme as it is now formed.” 
NAWASCHIN (17) published another paper on Lilium Martagon 
in 1910, again emphasizing the fact that the mature nuclei are 
capable of movement. He finds that the mitosis of the 2 male 
nuclei in the pollen tube is characterized at an early stage by sharply 
differentiated chromosomes, so that the sperm nuclei do not reach 
