366 



BOTANY. 



into four cells (C, Fig. 250), and from these the young plant 

 of the asexual generation is developed. The young plant is 

 quite simple, having small internodes, bearing sheaths which 

 contain but three leaves ; lar- 

 ger shoots soon arise, with lar- 

 ger internodes and sheaths hav- 

 ing more leaves, and these are 

 followed by others still larger, 

 until at last the full size is 

 reached. 



479. The spores of the 

 Equisetinae are produced either 

 upon the ordinary green stems, 

 as in Equisetum limosum and 

 E. hyeniale, or upon colorless 

 or brownish stems, which de- 

 velop early, and, after bearing 

 the spores, die and disappear, 

 as in E. Telmateia and E. 

 arvense. The sporangia are 

 developed upon m o d i fi e d 

 leaves, upon the ends of the 

 stems. The spore - bearing 

 leaves, like the ordinary ones, 

 are in whorls ; each leaf is, 

 however, peltate in form, and 

 borne upon a short stalk (st, 

 Fig. 251, B}. These peltate 

 leaves (usually called the pel- 

 tate scales) are collected into 

 . cone-shaped clusters, and by 



their mntual p ressure each 



een cut o ; y, section of the rachis of scale becomes more Ol' leSS 

 the ppike. U, peltate scales, #, s, in . ... TT 



various position* (slightly matrniflert) ; hexagonal 111 Outline. Upon 



*ff, the sporangia borne on the under side ,, , . . , , 



of the scales ; gf, st, the pedicels of the the Under SUrfaCC of each SCale 



there arise five to nine or ten 



cellular masses, which enlarge and become sac-shaped spo- 

 rangia ; certain inner cells become spore mother-cells, and 

 from each of these four spherical spores are produced. The 



