1918] NOTHNAGEL—FERTILIZATION 161 
Fic. 17.—Lilium Martagon; same stage as fig. 16, the three nuclei being 
curved, 8 being more curved and chromatin coarser. 
1G. 18.—Later; fibers are appearing about nuclear complex. 
Fic. 19.—Showing two components of primary endosperm nucleus in which 
the decusatis is collecting in heavier strands and separating nuclear mem- 
branes are still evident. 
1G. 21.—Late spirem; separating nuclear membranes still divide the three 
spirems; fibers wie sues to races out into cyroplasit. 
IG. 22.—Next endosperm nucleus as seen in fig. 21. 
r J 
PLATE V 
Fic. 20.—Formation of spirem, the three nuclei still separate. 
1G. Loe —Three groups of chromosomes upon a tripolar spindle. 
Fic. 24.—Slightly later stage; third group is being pulled i in with other 
two groups to form bipolar spindle. 
G. 25.—Bipolar spindle of first sili of primary endosperm nucleus, 
third _— of chromosomes still separa 
G. 26.—Slightly later stage; all pr ria of groups of chromosomes 
lost; “htenicaiiies beginning to split longitudinally 
1G. 27.—Telophase of first division of primary endosperm nucleus. 
Fic. 28.—Third division of endosperm nucleus in Trillium grandiflorum, 
showing 3 groups of chromosomes upon bipolar spindle. 
Fic. 29.—Second division of endosperm nucleus, upper one showing three 
groups of chromosomes. 
