30 MOSSES AND LIVERWORTS 



time it begins to swell, and presently the inner 

 of the two coats or membranes bursts through 

 the outer one in the form of a very fine thread- 

 like growth, which grows and branches in various 

 directions, often, and especially if moisture is 

 present, increasing with considerable rapidity. 



This first growth from the moss-spore is known 

 as the Protonema of the moss. Tangled masses 

 of these delicate threads, looking like soft green 

 velvet, may frequently be seen on the surface of 

 the earth in moist situations as, for instance, on 

 the soil in the flower-pots of a greenhouse, or in 

 the nooks and corners in the banks of a stream. 

 When examined with a good glass, or under the 

 microscope, they will be found to consist of 

 a succession of long, narrow cells, as shown in 

 fig. 2 of Plate III., where I have drawn, on a 

 somewhat large scale, a very small portion of one 

 which was developed from a spore of that very 

 tiny moss, the Serrated Earth-moss (Ephemerum 

 serratum), which, as I have already stated, grows 

 in fallow-fields, and in similarly exposed positions, 

 and is so minute that nothing but a close and 

 careful scrutiny of the ground will avail to 

 discover it. It is especially interesting to the 

 bryologist from the fact that, whereas in most 

 mosses the thread-like growth dies away at an 

 early period in the plant's history, in this one, 

 as also in a few others, it frequently has a much 

 longer existence, and consequently provides us 



