TYPES OF CRYPTOGAMS; PTERIDOPHYTES 



295 



and note the effect. Also note the effect of drying. How does this 

 affect the spores ? Use of the bands ? 



365. Germination of Spores. The spores germinate while fresh 

 and form prothallia corresponding to those of ferns, but generally 

 dioecious. The prothallium which bears the antheridia remains 

 comparatively small, and the antheridia are somewhat sunken. The 

 others grow much larger and branch profusely. 



The terminal portion becomes erect and ruffled. 

 Near this part the archegonia are formed, quite 

 similar to those of ferns. The embryo plant 

 developing from the germ-cell has its first leaves 

 in a whorl. This at length grows into a spore- 

 plant like that shown in Fig. 213. 



About twenty-five species of Equisetum are 

 known. Several may be looked for in any 

 locality and may well be compared with the one 

 described above, in regard to form, mode of 

 branching, and mode of fruiting. 



366, Fern-Plants (Pteridophytes). - 



The Pteridophytes (literally fern-plants) 

 include in their general category not only 

 ferns as commonly recognized, but several 

 other small groups which are very inter- 

 esting on account of their diversity. All 

 cryptogams higher than mosses belong in 

 this group. In moss plants the individ- 

 uals growing from spores and bearing 

 antheridia and archegonia, the gameto- 

 phytes, are full-grown leafy plants, and 

 the spore-bearing plant, or sporophyte, is 

 merely a stalk bearing a sporangium. In 

 all the fern-plants the reverse is true. 

 The individuals growing from spores and 



, . , . ,. , . a, mouth of a ferti- 



bearing antheridia and archegonia are of iized arcnegomum. 



FIG. 214. Part of a 

 Lobe of the Mature 

 Female Prothal- 

 lium of Equisetum. 

 (x about 50.) 



