THE BOOK OF NATURE STUDY 



into three parts (i) the peaked lid, (2) the square spore case, 

 (3) a swelling separated from the spore case by a groove ; the 

 swelling, however, strictly forms part of the stalk. When the 

 lid falls off, or is picked off, one sees a flat membrane across the 

 mouth of the capsule, and below this a ring of small pores 

 (usually sixty-four) separated by short bars ; these bars are the 

 peristome teeth, across whose tips the membrane is stretched. 

 It is easy to see how this mechanism causes the spores to be 



dusted out gradually when the 

 nodding capsule is shaken by 

 the wind. The mechanism is 

 similar to that of a poppy cap- 

 sule. 



There are several other kinds 

 of hair-moss, varying consider- 

 ably in habitat . The commonest 

 one in woods (P. formosum) is 

 smaller than the heath kind, and 

 its leaves have less power of 

 movement, neither standing out 

 so far when moist nor closing 

 up so completely when dry. 

 Another kind (P. pilifemm), 

 common in dry, sandy, or stony 

 places, is still smaller (about an 

 inch and a half high), and is 

 well adapted to its habitat. 

 The rolling up of the leaf is 

 very marked, the scaly wing- 



FiG. 28. Peristome of Hair Moss, magnified. n ., . c , , - .. . 



A, side view ; B, view from above. llke margin of the leaf being 



easily seen in this species, which 



is rendered conspicuous by its bright orange or scarlet male 

 flowers, and the golden hood over the capsule. 



The Wavy Hair Moss (Catherinea undulata, Fig. 29), very 

 common on sandy or clayey soil in woods, fruits in late autumn 

 and winter. The capsule is slender and strongly curved, though 

 the stalk is straight, and its lid has a curved beak (often nearly 

 as long as the capsule itself), while the hood is thin and 



