8 



Shortly after this Guignard^ described the same phenomenon more in 

 detail. Previous to the.^* discoveries it had been supposed that in 

 fecundation onlv one of the two generative nuclei which are formed 

 in the pollen tube of seed plants passed over into the embryo sac and 

 united with the egg cell proper. Nawaschin tuid Guignard have 

 shown, however, that both of the nuclei enter the embryo sac, one 

 fusing with the nucleus of the egg cell and the other with the two 

 polar nuclei to form the embrj^o sac nucleas, the division of which 

 gives rise to the endosperm. If this double fecundation occurs in 

 hybridization, it will be seen that the endosperm developed from the 

 nucleus of the embryo'sac must be of hybrid origin. Guignard also 

 called attention to the more or less spiral form of the male generative 

 nuclei and designated them antherozoids. This form of the nucleus 

 which is suggested as being similar to the motile male cells of the 

 higher cryptogams and cj^cads is very peculiar and suggestive. 



No ver}^ recent researches on the embryology of corn or any of the 

 cereals or grasses have been made, and no direct observations are thus 

 extant to show that double fecundation takes place here. In 1893, 

 Golinski,^ in an article on the development of the androecium and 

 gynoecium in grasses, described the elongated spiral form of the gen- 

 erative nuclei in wheat and rj^e. In this case the two nuclei are 

 formed in the pollen grain before its germination. Golinski describes 

 them as not unlike the antherozoids of the 0/uiracecB and ferns. In a 

 recent article MerrelP describes the occurrence of similar elongated 

 spiral nuclei in the case of Silphium^ where also thej^ are formed in 

 the pollen grain before germination. This form of the male gener- 

 ative cell probably is not correlated with double fecundation; but, in 

 the present state of our knowledge, it is at least suggestive, as this is 

 the peculiar form of the generative nuclei in LiHuiii and other plants 

 where double fecundation has been o])served. Since the publication 

 of Guignard's paper the spiral antherozoids of LiUmii martagon and 

 the union of one of them with the embryo sac nucleus have also been 

 observed by other investigators.* Last summer Dr. Scott, Director 

 of the Jodrell Laboratory, Kew, England, kindly showed the writer 

 slides prepared by Miss Sargant, plainly illustrating this phenomenon, 

 and later the wn-iter also had the pleasure of examining the prepara- 

 tions of Guignard which very plainly showed the stages which the 

 latter figured. It would seem thus that double fecundation undoubt- 



' Guignard, L. Sur les antherozoides et la double t-opulation sexuelle t-hez les 

 vegetaux angiospermes. Rev. gener. d. Bot., T. 11, pp. 129-135, 1899, and Comptes 

 renduj? d. seances d. I'Acad. d. Sci., T. 128, p. 869, 4 avril, 1899. 



2 Golinski, St. J. Ein Beitrag zur Entvvicklungsgeschichte des Androeceums und 

 des Gynoeceums der Griiser. , Bot. Centralblatt, Bd. 55, Nos. 1-6. 1893. 



^Merrell, William Dayton. A Contribution to the Life History of Silphinm. 

 Botanical Gazette, Vol. 29, p. 113. Fel)., 1900. 



^Sargant, Ethel. Proceedings Royal Soc, Vol. 65, p. 163. 1899. 



