Vlll EXPLANATION OF THE PLATE. 



Figs. 12 — 18. Formation of the emhryo iii Orcliib Morio 



(from Hofnieistcr). 



Fig. 15. Tlio ovule, a considerable time before fertilization, a, tlie outer 

 coat ; h, tlie inner coat j s, the embryo-sac ; c, tlie funiculus. 

 Three nuclei have been formed in the niieropyle end of the 

 embryo-sac. 



„ 13. The internal parts of the ovule a short time before fertilization, 

 a, inner coat of the ovule ; s, embryo-sac ; h, germinal vesicle, 



J, 14. The ovule at the moment of fertilization, a, h^s^dih in the pre- 

 ceding figure ; p, the pollen -tube ; f, a few cells wliich have 

 made their appearance at the chalazal end of the embryo-sac. 



jj 15. Further development of the impregnated germinal vesicle. It 

 contains two nuclei which lead to its division hito two cells. 



„ 16. The embryo-sac with a pollen-tube adherent. The germinal 

 vesicle is parted into two by division into an uj)per {a) and 

 a lower (5) cell, 



„ 17. The pi;o-embryo (VoTheim). Its superior portion {c(), the sus- 

 pensor, has originated through the division of the cell a of 

 Fig, 16 ; its inferior portion, the rudiment of the embryo (/;) 

 through the division of the cell h of Fig, 16. 



18. An embryo (5), with its suspensor («), in a farther advanced 

 stage of development. 



Fias. 19 — 33. Spores of Prolifera rlvKkms (ixom Thuret). 



19. Moving spore possessing a circle of cilice. 

 20 — 22. Yarious stages of the germination. 



23. Two ciliated spores of Oo^ifervcff ylomerata (from Thuret). 



24. Orermination of the same (from Thuret). 



25. Seminal filaments {Smnenfaden^ spermatozoich) of Chfra (from 

 Thuret). 



26. Two cells from the antheridium ofHplmgtiim^ with seminal ii la- 

 ments (from linger). 



27. An isolated seminal filament (from linger). 



28. A seminal filament with two ciliac treated with iodine. 



29. Seminal filament of Puru serridata (from Lcbzcyc-Suniinski). 



iD 



5> 



