The Formation of the Sexual Nuclei in 
Lilium Martagon. 
I. Oogenesis. 
BY 
ETHEL SARGANT. 
With Plates XXII and XXIII. 
S OME recent zoological observations show that in certain 
cases a transverse division of the chromosomes occurs 
during one of the karyokinetic divisions immediately pre- 
ceding the formation of either sexual nucleus 1 . This is suf- 
ficiently remarkable, as the solitary exception to the rule of 
longitudinal fission of the chromosomes during karyokinesis. 
But it has further been shown that if future research should 
establish the general law that the formation of a sexual 
nucleus is always preceded by a transverse division of 
1 See the references (p. 97) in Dr. Haecker’s paper : ‘ The Reduction of the 
Chromosomes in the Sexual Cells as described by Botanists ’ — Ann. of Bot., ix. 
1895. 
Annals of Botany, Vol. X. No. XXXIX. September, 1896.J 
