BRYUM. 59 



double (fig. 42), or composed of an outer and an inner 

 row of teeth. The outer row consists of sixteen ob- 

 lique reddish teeth, which are marked with trans- 

 verse bars or trabe'culae (trabecula, a little beam), and 

 their points are connected by a net-like thin plate. 

 The inner row contains also sixteen teeth, arising 

 from the division of the membrane lining the cap- 

 sule ; these are yellowish, thin, and placed opposite 

 the outer teeth. The capsule itself is pear-shaped or 

 pyriform, orange-red when ripe, curved, and with the 

 mouth oblique. The calyptra (fig. 36) is half-cleft, and 

 expanded as if blown out below. The lid (fig. 31 a) 

 is convex and obtuse ; and the annulus (fig. 39) is 

 large and easily separable. The fruit-stalks are 

 curved near the top. The leaves (fig. 30) are ovate, 

 concave, entire, with a nerve reaching the apex, 

 which is acute and prolonged into a little point, or 

 apic'ulate. The spores (fig. 38) are small and reddish 

 brown. The specific name (hygromet'ricd) of this 

 moss expresses its hygrometric property ; for if either 

 the recent and moist moss be dried or the dry moss 

 wetted, the fruit-stalk gradually twists in opposite 

 directions in the two cases. 



The last of the Acrocarpous mosses which we shall 

 notice, Bry'um capiHare (PI. III. fig. 49), is tolerably 

 common on trunks of trees, on the ground, and 

 sometimes on walls. 



The capsule of this moss has a double peristome 

 or mouth-fringe ; the outer consisting of sixteen red- 

 dish-brown, equidistant, transversely striped teeth; 

 the inner composed of sixteen thin keeled teeth, more 

 or less split down the middle, and with two or three 

 intermediate cilia. The capsule is nodding, smooth, 

 oblong, pear-shaped, slightly narrowed below the 

 mouth ; the lid being somewhat convex, and furnished 

 with a short slender beak. The calyptra is dimidiate. 

 The leaves (fig. 50) are obovate, the nerve extending 



