Mosses and Lichens 



Greek words, <J>VCTKWV, a fat paunch, and pnpCov, a conical cap. 

 The two words together describe the veil (calyptra) as a conical 

 cap with an inflated base. 



i Top-moss, Physcomitrium turbinatum, Muell. ined. See 

 Plate XVI. 



Habit and habitat. Top-moss is everywhere common in 

 old fields and grassy open places in gardens. It is conspicuous 

 both with and without spore-cases, and maybe easily recognised 

 from its picture. In September and October the bright-green 

 rosettes of both male and female plants may be found in loose 



Young plant 

 with spore-case 

 immersed. 



Spore-case with 

 veil. 



Physcomitrium pyriforme, Brid. Ideal 

 vertical section through a green spore- 

 case. 



Lid. 



Spore-cas* with lid. 

 P. turbinatum. 



clusters growing on the ground in protected spots, and if exam- 

 ined with a compound microscope, may reveal the archegonia 

 and antheridia. About the middle of May the same locality 

 should show colonies of plants with their perfect spore-cases on 

 slender pedicels (seta). One is almost sure of finding this moss 

 about flower-pots in green-houses where the ground has not 

 been too recently worked over. The shape of the spore-cases, 

 the contraction below the mouth of the dry spore-case and the 

 amount of thickening of the elongated cells about the mouth, 

 and the degree of roughness of the spores, all depend upon the 

 stage reached in their development before they become dry and 

 shrivelled; and again the stage in their development depends 

 upon the amount of rain and heat in their environment. 



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