EMBRYO AND ENDOSPERM 



II 



nuclei. Fertilisation is a double process, as shown by Navashin 

 and Guignard in 1899 (^/- Stenar, 1928 ; j0rgensen, 1928 ; Dahlgren, 



P/at\t' or SjboroJbAyhi 



> 



2a 



S 



E,S,M£ 



\ (Metosfs) ^ 



Te,t-rac( 



Te,rracf 



fmbryo sac 



or 



g aa/mfbJt>Ay/i 



{Fert/'/is 0//0 a) 



ra/A 



d* ga/n^tojbAyte 



fmbryo 



fndosjber/n 

 (5n) 



Fig, 3. — Life cycle of a flowering plant, an hermaphrodite dicotyledon, 

 showing the history of one pair of chromosomes in the haploid, 

 diploid and triploid phases. 



1927, 1930 ; Gerassimowa, 1933 on Crepis ; Poddubnaja-Arnoldi 

 and Dianowa (1934) on Taraxacum ; Hoare (1934) on S cilia ; 

 Mahony (1935) on Fagopyrum ; cf. Shimamura (1935) on Ginkgo). 



