292 Kansas Academy of Science. 



Order VII. HYDROPTERIDALES : The Water Ferns. 



carp and grows in the direction of a neighboring archegonium 

 within its gynosporocarp, the tissues of which it penetrates after 

 rupture of the outer wall; through this tube or tunnel the spermato- 

 zoids (antherozoids) pass to the ovum in the archegonium still 

 within its sporocarp, which has ruptured its outer wall in order to 

 allow of fertilization. This is another long step forward in the 

 new mode of impregnation— a step that once taken is never after- 

 ward wholly abandoned, but pervades the fecundating mechanism 

 of the entire carpellate subkingdom in the shape of a pollen tube. 

 The mature oospore, in a new protecting case which actually con- 

 tains the entire archegonial gametophyte, in that respect resem- 

 bling a seed, finally becomes separated from the parent sporophyte 

 which may have perished, and, being in a suitable place, with all 

 required conditions favorable, may germinate and grow into a new 

 floating-fern or water-fern sporophyte. Thus this complicate 

 process, commonly called "alternation of generations," or hetero- 

 genesis, under such adverse conditions, is continually repeated. 

 No wonder the plants are rare in Kansas. They require a humid 

 climate and gentle movements of air and water. But the process 

 of fecundation is adopted by nearly all the seed-bearing plants; 

 plants that perform their breeding functions in air, not in water; 

 plants that are better adapted to the surrounding conditions than 

 the poor little water-ferns. 

 Although they are very rare, yet the few to be found in Kansas belong 

 to two distinct families. 



Family 21. Salviniace^ : Floating-fern Family. 



155. AzoUa caroliniana Willd. Carolina floating-fern. Found in 



Cloud county by Professoi Schaffner; also Burlington, 

 Coffey county. (S) 



Family 22. Marsileace^: Water-fern Family. 



156. Marsilea vestita Hooker & Greville. Four-leafed water-fern. 



Wet or damp sandy hollows, such as old ' ' buffalo wallows, ' ' 

 which dry in summer, Washington, Cloud, Saline, Barton 

 and Greeley counties; rare. July. (A S U) 



Order VIII. ISOETALES : The Quillworts. 



( Heteroaporous Eusporangiate Stereocaulones.) 



Pteridophytic plants in which the sporophores bear two forms and sizes 

 of spores, namely, very small androspores bearing the antherozoids, 

 and very large gynospores bearing the ova. These are all de- 

 veloped in sporangia formed from groups of epidermal and subepi- 

 dermal cells. The antherozoids within the androspores are motile, 

 microscopic, multiciliate, and spiral. A single ovum with its case 

 (sporocarp) fills each gynospore. 



Sporophytes with an erect, exceedingly short and comparatively broad 

 stem or trunk, with a dense tuft of rootlets and no cauline leaves. 

 This naked, button-shaped stem is crowned with a compact ro- 

 sette of broad, erect sporophyls with excessively prolonged chlo- 

 rophyl-developing tips, sometimes a decimeter high, resembling 



