DEVELOPMENT OF THE SPOROGONIUM IN THE MOSSES. 283 
(26) Vaızey, J. R.—Note on “ The Transpiration of the Sporophore of 
the Musci.” Annals of Botany, Vol. i. no. 1 (Oxford, 1887). 
(27) VALENTINE, W.—Observations on the Development of the Theca 
and on the Sexes of Mosses. (Communicated May 1833.) Trans. 
Linn. Soe. vol. xvii. 1835. 
DESCRIPTION OF THE PLATES. 
Prats IX. 
Fig. 1. General view of theca of Polytrichum commune, with a portion of the 
seta. S.=seta; ap.=apophysis; s/.-region upon which the sto- 
mata are developed ; sy.=sporangium; pé.—annulus; L.—lid. 
2. The foot of the sporogonium of P. commune. | v. —vaginula ; ft.=foot ; 
S. — seta. 
3. (^ commune. Letters as for fig.l. d=left side or angle; r- right 
4. side; p—posterior side; a=anterior side. 
5.'P. formosum. Letters as for fig. 1. 
6. Letters the same as in figs. 1 and 2. Various stages of development of 
the sporogonium of P. formosum from (a) the youngest to (c), in which 
the rudiments of all the parts can be made out. 
7. Young eporogonium of stage of fig. 6 (a), X about 11. 
8. Young thecs of P. formosum. Letters as in fig. 1. 
a. The young theca is just visible, —stage figured by fig. 6c. 
b. At this stage the position and limits of the lid can be seen. The apo- 
physis cannot yet be distinguished from the sporangium. 
c. Rather later stage than b. The apophysis is being formed. At this 
stage the young stomata are forming, but are not yet open. 
d. Nearly mature theca. The angles have not yet been formed ; a sec- 
tion through the theca at this stage is nearly circular. 
9. Transverse section through the apophysis of P. commune, x40. ep.— 
epidermis; c.—cortex ; ¢.s.=central strand, the limits of which are not 
clear in this region. 
10. Transverse section of the seta of Funaria, a form in which there are 
no intercellular spaces in the cortex of the seta. Letters as in 
fig. 9. 
ll. Longitudinal section of the seta of Atrichum undulatum, x 300. ep.— 
epidermis; c.=cortex; $.—intercellular spaces; c.8.— central strand ; 
sh.—parenchymatous sheath of c5; 0¢.=leptophloém; ac.=lepto- 
xylem. . 
12. Cells of the cortex of Atrichum undulatum (longitudinal section) 
stained with Hoffmann's blue and treated with Schulze’s solution. p.= 
protoplasm of cell; sc.=swollen cell-wall; md.=middle lamella; 
n.=cell-nucleus. 242 
A 
