196 ROBERT H. BOWEN. 



EXPLANATION OF PLATE I. 



Figures i, 2, 4, 6 and 7 are from root-tips of Viciafaba; Fig. 3 from Hyacinlhns; 

 Fig. 5 from Ricinus; Fig. 9 is from Polytriclmm juniperinum; Figs. 8, 10, n and 

 13 are from P. commune; Figs. 12 and 14 to 19 are from P. piliferum. Figs, i to 

 7 and 9 are reproduced at a magnification of approximately 1125 X; Figs. 8 and 

 10 to 19 at 2475 X. 



FIG. i. Osmiophilic platelets. Kolatchev. 



FIG. 2. Plastidome in an early prophase. Benda. 



FIG. 3. Osmiophilic platelets, plastidome and pseudochondriome. Kolatchev. 



FIG. 4. Pseudochondriome. Champy-Kull. 



FIG. 5. Vacuome. Weigl. 



FIG. 6. Osmiophilic platelets, plastidome and vacuome. Kolatchev. 



FIG. 7. Vacuome and Osmiophilic platelets. Weigl. 



FIG. 8. Early androgonia. Kolatchev. 



FIG. 9. Tip of an antheridium with androgonia in a middle phase of multipli- 

 cation. Weigl. 



FIG. 10. Early androgonium. Champy-Fe-hematoxylin. 



FIGS, ii TO 14. Later phases of limosphere formation. Fig. 11 is viewed 

 from one pole and does not show the nucleus. Kolatchev; Figs, n and 13 counter- 

 stained with acid fuchsin-aurantia. 



FIGS. 15 AND 1 6. Centriole and tail filament in earlier sperm-forming stages. 

 Benda. 



FIGS. 17 AND 18. Stages in the deposition of the acrosomal material. The 

 heavily stained periphery of the limosphere is now known to have little if anything 

 to do with the Osmiophilic platelets. Allen's fluid-Fe-hematoxylin. 



FIG. 19. Early elongation of the acrosome. Benda. 



