1921] WALKER—GAMETOPHYTES OF EQUISETUM 301 
6. JEFFREY, E. C., The development, structure, and affinities of the genus 
Equisetum. ein: Boston Soc. Nat. Hist. 5:no. 99. 
SHYAP, SHIv Ram, The structure and development . os prothallus 
7, 
of Equisetum debile Roxb. Ann. Botany 28: 163-181. 
8. ———,, Notes on Equisetum debile Roxb. Ann. Botany 31 ae 445. IQ17 
9. Sacuein: R., Die Entwickelung des Keimes der Schachtelhalme. Jahrb. 
Wiss. Bot. 11:575. 1878. 
EXPLANATION OF PLATES XXIII, XXIV 
PLATE XXIII 
ia 1-5.—Gametophytes attached to soil; X 2. 
Fic. 6.—Under side of gametophyte in fig. 1 showing peripheral meristem, 
cleared in glycerine; X11 
Fic. 7. LCdaetephyts with five sporophytes at periphery; X 2. 
Fic. 8.—Freehand vertical section of gametophyte showing massive 
parenchyma with upright branches and peripheral meristem bearing arche- 
gonia; X12. 
Fic. 9.—Vertical section of gametophyte showing two antheridia and one 
sporophyte; 12 
Fic. 10. ney ee gametophytes with soil removed (photographed under 
water); X2. 
Fic. 11.—Part of vertical section of gametophyte with sporophyte shown 
in text fe. 1 at right; 18 
PLATE XXIV 
Fics. 12, 13.—Parts of horizontal section through peripheral meristem 
showing brelve antheridia and one archegonium; X 
Fic. 14.—Vertical section of archegonium with ‘you sporophyte in 
venter; ><120, 
IG. 15.—Vertical section showing at left two antheridia; at right (A, A) 
necks of two old archegonia; X 50. 
Fic. 16.—Horizontal section; above two antheridia intact; to their right 
and left (B) old ruptured antheridia; at extreme right (A) an old arche- 
gonium; X50 
Fic. 17 peeeee, sheep sett two antheridia and archegonium con- 
taining sia sporophyt 
F —Vertical see e upright branch with antheridium below 
tip; iy 
Fic. 19.—Horizontal section; upper of three antheridia ruptured; X60. 
