igiS] HUTCHINSON— MALE GAMETOPHYTE OF PICEA 299 



18. Lopriore, G., tjbcr die Vielkornigkeit tier PoUenkorner von Araucaria 

 Bidwillii. Ber. Deutsch. Bot. Gesclls. 23:235-246. 1905. 



19. Thompson, R. B., Preliminary note on the Araucarineae. Science N.S. 

 22:88. 1905. 



20. Burlingame, L. L., The staminate cone and male gametophyte of 

 Podocarpus. Bot. Gaz. 46: 161-17S. 1908. 



EXPLANATION OF PLATES XV-XIX 



The drawings (figs. 1-53) have been made with the aid of the Abbe camera 

 lucida. The original magnification was 2000. A reduction of one-half has 

 been made in reproduction. 



Figs. 1-13. — The first primary division; the primary cell retains its iden- 

 tity; the first primary wall cuts off an antheridial cell. 



Fig. 1. — Primary cell. 



Fig. 2. — A division at right angles to the longitudinal axis. 



Fig. 3. — A division in the plane of the axis; a chromatic extrusion is be- 

 ing formed and is separating from the nuclear chromosomes. 



Figs. 4, 5. — Telophases: the primary nucleus and spindle fibers sepa- 

 rating. 



Figs. 6, 7, 8, 11. — Telophases: each shows the cell plate in one of 4 

 positions; in fig. 8 both nuclei have escaped from the spindle fibers. 



Figs. 9, 12. — Two free nuclei in common cytoplasm; compare fig. 8. 



Figs. 10, 13. — The primary cell has given rise to two daughter cells, each 

 of which may function as a sister primary cell. 



Figs. 14-27. — The second primary division. 



Fig. 14. — The primary cell in contact with the first evanescent antheridial. 



Figs. 15, 16. — Prophases. 



Fig. 17. — Anaphase: spindle fibers indistinct. 



Figs. 18-25. — Telophases: illustrate migration of primary nucleus and 

 spindle fibers; fig. 24, a view from upper pole; figs. 23-25, the formation of 

 the cell wall. 



Figs. 26, 27. — Pollen grains with primary cell and two non-functioning 

 antheridial cells; compare size with fig. 1. 



Fig. 28. — First antheridial ("prothallial") cell in division. 



Fig. 29. — Primary cell; also first and second antheridial cells; the former 

 has divided to form two nuclei. 



Fig. 30. — First antheridial cell has divided to form a spermatogenous and 

 sterile cell. 



Figs. 31, 32. — Two sister primary cells (cf. figs, n and 13) have given 

 rise to a bi-antheridial gametophyte (disintegration). 



Fig. ^s- — Four free nuclei, products of first antheridial cell; the primary 

 cell and second antheridial cell disintegrating. 



Figs. 34-36. — Chromatic extrusions. 



