368 



MUSCINF.JE. 



surface of the ground from the lime that the spores become ripe till the next 

 autumn, when the root-hairs again produce a new protonema, and upon this new 

 stems arise. 



Similar "outgrowths from the roots occur also, according to Schimper, in 

 the felted protonema of some species of Polytrichum (P. nanum and aloides) on 

 the slopes of hollow roads, and on that of Schistoslega osmundacea in dark hollows. 

 The root-hairs may also immediately produce leaf-buds, and behave, in this respect, 

 exactly like the protonema. When the buds arise on underground ramifications 

 of the root-hairs (Fig. 250, B) they remain in a dormant state, as small microscopic 



Fig. •2<,o.—A young plant of a Barhula (m) with the root-hairs h, to the gfrowingf ends of which particles of earth have 

 become attached; at / a superficial root-hair is putting out -branches containing chlorophyll, in other words a protonema; 

 at ^ a tuberous bud (bulbil) is growing from an underground branch of the root-hairs ; R this bud more strongly magnified 

 (^ X 20 ; i? X 300). 



tuberous bodies {bulbils) filled with reserve food-material, until they chance to 

 reach the surface of the ground, when they undergo further development {e.g. 

 Barbula muralis, Grimmia pulvinaia^ Funaria hygrometrica, Trichostomum rigidum^ 

 Atrichum). The aerial root-hairs may, however, not only produce a protonema 

 containing chlorophyll, but also leaf-buds without its intervention ; and Schimper 

 cites the remarkable fact that in Dicranum undulalum annual male plants are 

 formed in this manner on the tufts of perennial female plants, and fertilise the 

 latter. 



Even the leaves of many Mosses produce a protonema, their cells simply 

 growing, and the tubes thus formed becoming segmented. This occurs in Oriho- 



