266 ? BOTANICAL GAZETTE [SEPTEMBER 
precedes fertilization. In the higher plants cell and nuclear 
union have been thought to come close together at the beginning 
of the sporophyte generation, while the chromosome union did not 
occur until during the reduction division at the end of the sporo- 
phyte generation. In ‘Abies, as found by HurcuHinson; in 
Stangeria, according to CHAMBERLAIN; and in Lilium there seems 
to be evidence of a chromosome union at the time of fertilization. 
Summary 
r. The egg nucleus is in a resting condition when the male 
nucleus, in spireme stage, comes in contact with it. 
2. Distinct male and female spiremes are formed which are 
segmented into chromosomes while the nuclei are in contact. 
3. On the equatorial plate the male and female chromosomes 
come together in x number of pairs and divide by means of a 
transverse break, each pair forming 4 segments. The segments 
move to the poles in pairs. Of the 4x segments formed, 2x go to 
each pole of the spindle. 
4. The chromosomes on the equatorial plate of the second 
division of the fertilized egg divide longitudinally. 
5. The endosperm nucleus divides at least twice before the 
fertilized egg undergoes division. 
6. A distinct spireme is formed in each of the nuclei of the triple 
fusion, and the 3x segments are oriented on the equatorial plate. 
_ 7. The endosperm nucleus divides in the typical vegetative 
manner by means of a longitudinal splitting of the chromosomes. 
EXPERIMENT STATION 
AGRICULTURAL CoLLEGE, N.D. 
LITERATURE CITED 
1. BrackmaN, V. H., On the cytological features of fertilization and related 
phenomena in Pinus silvestris L. Phil. Trans. Roy. Soc. London B 190: 
395-426. pls.12-14. 1808. 
2. BLACKMAN, V. H., and Wetsrorp, E. J., Fertilization in Lilium. Ann. 
Botany 27:111-114. pi. 12. 1913. 
3. CHAMBERLAIN, C. J., Oogenesis in Pinus Laricio. Bort. Gaz. 27:268-280. 
pls. 4-6. 1899. 
, Stangeria paradoxa. Bor. Gaz. 61:353-372. pls. 24-26. 1916. 
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