MICROSCOPIC STRUCTURE OF HIGHER CRYPTOGAMIA. 34:3 



Tonnded apertures, by which their cavities freely communicate with one 

 another, as is sometimes curiously evidenced by the passage of Wheel- Ani- 

 malcules that make their habitation in these chambers. Between these 

 -coarsely-spiral cells are some thick- walled narrow elongated cells, contain- 

 ing chlorophyll; these, which give to the leaf its firmness, do not, in the 

 very young leaf (as Prof. Huxley first pointed out 1 ) differ much in 

 appearance from the others, the peculiarities of both being evolved by 

 a gradual process of differentiation. The antheridia or male organs of 

 SphagnacecB resemble those of Liverworts, rather than those of Mosses, in 

 their form and arrangement; they are grouped in catkins at the tips of 

 lateral branches, each of the imbricated perigonal leaves inclosing a sin- 



fle globose antheridium on a slender footstalk; and they are surrounded 

 y very long branched paraphyses of cobweb-like tenuity. The female 

 organs, or archegonia, which do not differ in structure from those of 

 Mosses, are grouped together in a sheath of deep green leaves at the end 



Oblique section of footstalk of 

 Portion of the leaf of Sphamium : Fern-leaf, showing bundle of Sea- 



showing the large c^lls, a, a, a, lariform Ducts, 



with spiral fibres and communica- 

 ting apertures; and the intervening 

 bands, b. b, b, composed of small 

 elongated cells. 



one of the short lateral branchlets at the sides of the capitulum or sum- 

 mit-crown of leaves. The two sets of organs are always distributed on 

 different branches, and in some instances on different plants. The ' cap- 

 sule/ which is formed as the product of the impregnation of the germ-cell, 

 is very uniform in all the species; being almost spherical, with a slightly 

 convex lid, without beak or point, and showing no trace of a peristome; 

 and the spores it contains are produced in groups of four (as in Mosses) 

 around a hemispherical ' columella.' Besides the ordinary capsules, how- 

 ever, the SphagnacecB develop a smaller set of sporogonia, in which 

 ' microspores ' are formed by a further division of the mother-cells; the 

 significance of these is unknown. The ordinary spores, when germinat- 

 ing, do not produce the branched confervoid filament of true Mosses; but 

 if growing on wet peat, evolve themselves into a lobed foliaceous ( pro- 



1 See his important Article on ' The Cell-Theory ' in the " British and Foreign 

 dico-Chirurgical Review," Vol. xii. (Oct., 1853), pp. 306, 307. 



