Gnetum , with some Notes on the Structure of Inflorescence . 619 
8. The nuclei formed in the heterotypic division are free. 
9. The spindles in the homotypic division are arranged either bilaterally 
or tetrahedral ly. 
10. Cell-plates appear after the homotypic division, dividing the cavity 
of the mother-cell into four loculi, each containing one microspore. 
ir. While the wall of the microspore is being laid down, the septa of 
the mother-cell become almost as thick as its outer wall. Before the 
microspores are set free, exine and intine are differentiated, 
12. The outer wall and septa of the mother-cell are probably 
mucilaginous in character. They usually disappear gradually as if in 
process of solution. 
13. The microspore nucleus undergoes mitosis ; one of the two daughter 
nuclei divides again. There result three free nuclei which may show 
a radial or a linear arrangement. 
14. This appears to be the condition of the pollen when dehiscence of 
the anther occurs. 
15. The three nuclei are probably to be identified as one prothallial. 
one vegetative (tube), and one generative. 
16. The germination of the microspore and the structure of the pollen- 
grain point to a much closer degree of affinity with Welwitschia than with 
Ephedra. 
Botanical Laboratory, 
South African College. 
Literature. 
Bower, F. O. (’82) : The Germination and Embryology of Gnetum Gnemon. Q. J. M.S., vol. xxii, 
p. 278. 
Cooke, Th. (’07) : Gnetaceae. The Flora of the Presidency of Bombay, vol. ii, p. 665. 
Coulter, J. M. (’08) : The Embryo-sac and Embryo of Gnetum Gnemon. Bot. Gaz., vol. xlvi, p. 43. 
de Bary, A. (’84) : Comparative Anatomy of the Vegetative Organs of the Phanerogams and 
Ferns (Eng. Trans.). Oxford, 1884. 
Engler, A. (’08): Gnetaceae Africanae. Engler’s Bot. Jahrb., Bd. xl, p. 519. 
Ferguson, M. C. (’04) : Contributions to the Knowledge of the Life-history of Finns, & c. Proc . 
Wash. Acad. Sci., vol. vi, p. 1. 
Goebel, K. ((’00, ’05) : Organography of Plants (Eng. Trans.). Oxford., 1900, 1905. 
Griffith, W. (’54) : Gnetaceae. 1 Posthumous Papers. Notulae. Part iv, pp. 28-31. Calcutta, 
I ^54 i 
Hickling, G. (’07) : The Anatomy of the Palaeostaehya vera. Annals of Botany, vol. xxi, p. 369. 
Karsten, G. (’92) : Beitrag zur Entwickelungs-Geschichte einiger Gnetum-Arten. Bot. Zeit., 
Bd. 1, p. 205. 
(’93) : Zur Entwickelungs-Geschichte der Gattung Gnetum. Cohn’s Beitr. z. Biol. 
d. Pfh, Bd. vi, p. 337. 
1 I am indebted to Dr. B. Daydon Jackson, Sec. L. S., for his kindness in furnishing me with 
a copy of this paper. 
