STRUCTURE OF MOSSES. 



371 



protoplasmic substance to pass into an Amoeboid condition resem- 

 bling that of the gonidia of Yolvox (§ 198). The protoplasm first 

 detaches itself from contact with the cell- wall, and collects itself 

 into ovoid masses of various sizes ; these gradually change their 

 colour to red or reddish-brown, subsequently, however, becoming 

 almost colourless ; and they protrude and retract processes, exactly 

 after the manner of Amcebce, 

 occasionally elongating them- 

 selves into an almost linear 

 form, and travelling up and 

 down in the interior of the 

 tubular cells. This kind of 

 movement was observed by 

 Dr. Hicks to subside gra- 

 dually, the masses of proto- 

 plasm then returning to their 

 ovoid form ; but their ex- 

 terior subsequently became 

 invested with minute cilia, 

 by which they were kept in 

 constant agitation within 

 their containing cells. As to 

 their subsequent history, we 

 are at present entirely in the 

 dark; and the verification 

 and extension of Dr. Hicks's 

 observations constitute an ob- 

 ject well worthy of the atten- 

 tion of Microscopists. 



276. The chief interest of 

 the Mosses to the Microsco- 

 pist, however, lies in their 

 Fructification, which recent 

 discoveries have invested with 

 a new character. What has 

 been commonly regarded in 



that light— namely, the Capsule or Urn, borne at the top of a 

 long footstalk, which springs from the centre of a cluster of leaves 

 (Fig. 182, a)— is not the real fructification, but its product; for 

 Mosses, like Liverworts, possess both Antheridia and Pistillidia, 

 although these are by no means conspicuous. These organs are 

 sometimes found in the same envelope (or Perigone), sometimes on 

 different parts of the same plant, sometimes only on different 

 individuals ; but in either case they are usually situated close to 

 the axis, among the bases of the leaves. The Antheridia are 

 globular, oval, or elongated bodies (Fig. 183, a), composed of 

 aggregations of cells, of which the exterior form a sort of capsule, 

 whilst the interior are Sperm-cells, each of which, as it comes to 



b b 2 



Portion of the leaf of Sphagnum ; 

 showing the large cells, a, a, a, with 

 spiral fibres and communicating aper- 

 tures ; and the intervening bands, 

 b, b, b, composed of small elongated 

 cells. 



